Why does Cubase recognize only the quarter note as one beat in BPM?


When the BPM is 60 and the time signature is 4/4, there should be 60 quarter notes per minute, so we should get a total of 15 full bars.

When the BPM is 60 and the time signature is 6/8, there should be 60 eighth notes per minute, so when the time reaches one minute, exactly 10 full bars should be played. This is because each bar has 6 beats, and 6 beats multiplied by 10 bars equals 60 beats. However, when it reaches the one-minute mark, Cubase shows that 20 bars have already been played. How should I understand this issue?

Hi Steven, welcome to the Cubase community!

The confusion here might have a bit of something to do with how MIDI interprets time. Basic time keeping in midi is based on the notion of a constant length tick. Off hand, I believe Cubase uses a 480 ticks per quarter note as its default for the (again) usual default of 120BPM.

Look at it this way: If we continue to use quarter notes, at 6/8 (same as 3/4) the note length (in terms of time) is now only 3/4 as long, or 75% of they would be at 4/4. However, since we’re still looking at just how many musical bars we can get within a minute, we can see that we’re going to need more, now that the note durations are shorter (in absolute time).

If 4/4 at 60bpm gives you 15 bars, then 6/8 at 60bpm is going to give you 20.

By just looking at the bars you can visually tell you’ll need 1/3 more bars. Mathematically this is 15 / (6/8) = 20. For reference , you can see that at 4/4 you get 15 /(4/4) = 15.

An aside


I had multiple meters drilled into my head the hard way one day when I was working on a classical piece in Dorico that had staves playing at different meters, I think it was 2/4 against 6/8 or something, and I had to learn (after beating my head against the wall a thousand times), there that if I wanted the 2/4 bars to line up vertically with the 6/8 bars I’d have to cheat by using hidden tuplets in the 6/8 stave to make it work, since Dorico doesn’t yet handle metric modulation natively. This example isn’t the normal case for most music and it was actually an extreme one, but like anything extraodinary, we never forget it.

So it’s all bit fuzzy at the moment, but I learned enough there that I know exactly where to look (for the answers I need) if I ever run into those meter issues again.

Hope this helps.
:slight_smile:

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Thank you for your response! However, I believe this is a significant issue in music production, and could even be considered a serious bug. It makes the BPM setting quite different from a traditional metronome in daily life. Perhaps not using 8 as the denominator could solve the BPM issue, but when inputting MIDI notes, all the note durations would have to be doubled, which goes against our usual practice when writing sheet music. So, we always need to mentally convert the values to get the correct result, which can be quite exhausting. Tools should provide convenience and improve efficiency, not increase workload. Even if it’s a small amount of extra work, for professionals who often work ten-hour days or even all-night sessions, it can really become frustrating at times. I hope Steinberg will pay attention to this issue and resolve it as soon as possible.

I understand your frustration very, very well. I’ve been there, Steven. Trust me on this, it’s not a bug, it’s always been this way.

Considerer that no matter how you slice it, a minute remains a minute. It can never be any larger or smaller - it will always be exactly a minute.

There are some obvious truths we need to consider. We know that a quarter note @ 6/8 meter is only three quarter as long as a quarter note @ 4/4. There’s no argue there.

To prove this to yourself, create an empty Cubase file and add tempo and signature tracks.

  1. Set the tempo at the beginning of the track to 60. That value will never be changed.

  2. Next add a ruler track. Set it to seconds.

  3. Next set the meter at the start of the track to 4/4.

Now note where 60 seconds is at on the ruler. Took a really good look at which measure 60 seconds aligns to.

Now, leaving everything else completely untouched, change the 4/4 in the tempo track to 6/8.

Notice the minute (60 seconds) doesn’t change. It can’t. It’s an absolute constant. A minute is a minute. But the number of bars changes, indeed.

Why does this happen in MIDI? Because we haven’t really changed our playback tempo, have we? It’s still set to 60! We may have changed our meter, but not our tempo.

BTW, you’ll see that the metronome click in Cubase does actually adapt to whatever meter you set. Try it, you’ll see.

If we want the music to play faster we can use shorter notes and, we can do that by merely changing the meter. but then our music will end sooner, since our minute will still take exactly 60 seconds no matter what meter is in use. When viewed by a unit of a minute, we’ll have a lot of empty bars near the end, and that is where the additional bars come from - absolute time.

Hope this helps.

:slight_smile:


MIDI Beat Time

Musical timing is defined in fractions of a musical beat, so it makes sense to create a timebase that measures time as fractions of a beat. A quarter note is always one fourth of a whole note - regardless of the tempo. Similarly, a sixteenth note is always the same fraction of a beat. The rate at which the notes occur can change as the tempo changes, but the relative durations are always the same. So ideal timebase divides a musical beat into many small bits that occur at a rate determined by the current tempo. Each of these tiny fractions of a beat is called a tick, and the number of ticks per beat is independent of the tempo.

The SMF header chunk contains a 16-bit value that gives the number of ticks per quarter note. If it is not specified the MIDI default is 48 ticks per quarter note. This value is a constant over the whole file. Within the MIDI data stream are tempo meta-events, which contain a 24-bit value that give the number of microseconds per quarter note. Divide this one by the first one, include the time signature, and you get the number of microseconds per tick.

It is as you say, I have made a feature request for this:

However, with Cubase 14, there has been some improvement. If you use the new Score Editor and insert any tempo there, for example Dotted Quarter note = 60, you will see that this action will have an effect on the tempo track. It will change the tempo to 90 so that what you have written in the score sounds as it should. The parts (sheet music) will also have the correct tempo number on them (Dotted quarter = 60). The only exception would be the number in the tempo track window, and down in the Transport Panel, which will still read Quarter = 90.

Not completely perfect yet, but using the Score Editor of Cubase 14 really helps with this issue. Try it, even if you don’t really intend to hand out parts to musicians.

It’s a chiseled-in-stone MIDI standard. What ever PQN you set at the beginning to equal a quarter note - there it stays. It’s absolute.

In fact, within midi, notes are delineated as on/off events based upon how many ticks occur, and the ticks that occur per a quarter for a given tempo is constant.

Now, if you want to make notes shorter or longer than whatever that initial PQN and initial tempo gives you, you have two options. (Actually three)

  1. Change tempo. Everything plays faster or slower with no physical change (in tick time) of the notes. By modifying tempo you are actually changing the tick time rate - but the PQN remains the same.

  2. Make your notes shorter or longer. Keeping the same tempo (and consequently the same tick rate) you make your note longer or shorter and this physically changes the notes length (in number of ticks duration), yet those ticks still play out at the same tempo (rate of ticks).

  3. Both. Change the tick rate (tempo) and the number of ticks per note. Remember that the initial clock ratio of PQN doesn’t change it’s still 480,

The ratio of tick to quarter note ratio (PQN) is set once and only once at the beginning of a midi. Once that clock rate is set, it’s set for good. All we can do is modify later is to modify the tick rate via midi tempo, or to use more or less ticks (i.e. modify the meter).

Midi really only cares about that initial PQN (number) and the tempo (rate) based on it. It knows nothing about musical notation, and notes are merely on and off events measured in tick-based time.

Yes, a minute will always be a minute, and that won’t change. What I’m trying to discuss is why, under a 6/8 time signature at 60 BPM, we can’t have 60 eighth notes within one minute instead of 120 eighth notes. Isn’t that scientifically unreasonable?

When it comes to notation, it’s just a change in the unit of the note. We’re switching from a quarter-note-based time signature to an eighth-note-based one, but there should still be 60 beats (or units) per minute, right?

In fact, based on my understanding, at 60 BPM, each beat should last one second. No matter what the denominator of the time signature is (whether it’s 2, 4, 8, 16, or even 32), the length of each beat should be one second. What the software needs to do is either set the grid to the length of a quarter note as one second or set the grid to the length of an eighth note as one second. However, currently, no matter what the time signature is, the grid is always set to the length of a quarter note as one second. When the time signature switches to 6/8, even though the BPM is displayed as 60, the length of each eighth note is actually only 0.5 seconds. This doesn’t seem logical.

Yes, it is exactly as you say, and thank you for the solid information. However.

This is a case where we are trying to shape the man to understand the machine, when it could be worthwhile to shape the machine to indulge the man.

Other DAWs have this feature. Is it achieved through deception? Does the DAW hold the “real”, quantized, “machine generated” tempo inside, and indulges the user with lies? It could be, but that’s what’s desired. A very slow 6/8 affair, say eighth note at 48, is just that, and that’s what I expect to see on the screen (in every place relevant to it). I don’t really care if the DAW internally works with Quarter = 24 if that’s the only way.

We people don’t assign a length to a quarter note. It’s all symbolic. The quarter note might be the beat, or it may not be the beat. When it is the beat, all’s well. When it is not the beat, we have this minor “display discrepancy” which might confuse users that are not acquainted with the issue.

It’s reasonable, of course. But let me explain.

For starters, if you approach your composition from purely a notational approach, none of this is a problem. Dorico, is a great notation product for this. There, heedless of any midi limitations, you can enter your notation, and you can easily change meter wherever you like. You can change tempo anywhere you like, and it can based on beats per quarter note, beats per half note beats per eight note if you like. Dorico, as it builds the midi does the math for you so that whatever beat denominator you use will come out exactly at the rate (tempo) you desired.

Now, if your work the other way, say in terms of midi events to musical notes, you need to respect midi’s requirements and limitations. I’ll point out that all though I’m experienced in both Cubase and Dorico, I’ve not used Cubase’s Dorico-derived score editor yet.

Assuming you are mainly working from the midi angle and are working from the piano roll, you must positively understand the notion of PQN, and you need to know that it is set only once, and that fact is not up to Steinberg to make.

Simply put - the piano roll in Cubase is MIDI based, and must follow midi’s rules . It uses midi’s tick-based time clock. Should Cubase allow you any other notion of time elsewhere in the program, it is still going to be in relation to MIDI time and must be abstracted from it. Deception? No. Abstracted from - yes.

Really guys - I would suggest a deep dive on Google. Key up on MIDI, BPM, PQN and such. How are they are used in composing time within the MIDI world? How would one convert that to musical time? Heck, why not mosey on over to midi.org - the keeper of the standard - and grab a copy of the standard. It’s free to join. Sit back and enjoy a coffee, tea, beer, or whatever beverage is comforting, Read the references, scratch some numbers on paper and see how they add up. At some point, it’ll dawn on you. Then, you might understand the sheer amount of hackery needed to convert from one standard of timekeeping (midi) to musical time, to absolute clock time, and what magicians DAW developers must be, to hide all of that from our everyday concern.

I chose the strong word on purpose, to show that even then, it wouldn’t matter to me as an end user under the circumstances.

Personally, as a user, when we are working under common time signatures, say 4/4, I don’t care what happens under the hood. The same holds when I use compound time, or decide that a fast waltz would be better presented as Dotted half = 66 instead of Quarter note = 198. “Why? Isn’t it the same when you get down to it?” Yes, of course it is. But if this waltz later falls into a 4/8 section, again at 66, we are now discussing a Quarter Note at 132, which doesn’t have much to do with the original 198 at first sight, when in the first case, it’s still the same tempo.

To be honest, personally I don’t have a use for TPQN. Even when recording (instead of scoring), I have a clear picture of what note values I’m recording, into what time signature, and at what tempo. I have already decided if it’s going to be 4/4 at 100 full of eighth triplets, or a 12/8 at 100 full of eighths.

So, leaving the technicalities aside to those that can tackle them (or not), I just submit a feature request explaining how I would like the software to work, which is not irrational I think, as it is standard music theory. If it’s possible or not, it remains to be seen. Having the score editor impact the tempo track in Cubase 14 is hopeful news for me. Now, whether the “human tempo” should be displayed in the Tempo Track (that’s what the fuss is about), or if it should continue to display MIDI quarter notes per minute tempo instead
 this remains to be seen. (The conversion back and forth is already done as evident in the Score Editor).

As an ordinary user, I don’t fully understand the technical concepts and knowledge, but I’ll try to learn when I have time. However, I think if Dorico can correctly calculate the BPM when converting musical notation to MIDI, perhaps Cubase could use some technical method to eliminate the need for users to do the calculation themselves. For example, when BPM is set to 60 and the time signature changes from 4/4 to 6/8, I would need to divide the 60 BPM by 2, changing it to 30, to ensure that the length of each beat stays consistent in terms of time. If Cubase could automatically handle this step, it would make life much easier for ordinary users like me, and we wouldn’t have to feel frustrated with such problems while dealing with heavy workloads.

To put it simply, we just need Cubase to automatically divide the BPM by 2 in this case, while still displaying the original BPM.

I think it’s safe to say Cubase uses linear time. It’s just that midi basically uses quarter note relative time and notation does whatever it chooses. You’re right it’s not really the PQN as much as it the quarter note relative based time. Always the quarter based note in midi timing.

This is why a lot of folks use Dorico if they spend the majority of their time working with notation, then export it to midi then on into Cubase for more work.

So if 4/4 at 60 MIDI BPM gives you 15 bars per minute, then 6/8 converted to quarter note time is going to equal 20 bars per minute at 6/8 - in a strictly midi context.

Now, for Cubase to allow you to set a bpm based on any note denominator would be way, way cool feature, and very handy too. But it would be a major sea change as the piano roll is quite old and with it’s timing have traditionally been based on midi timing and such a new feature would never survive a conversion to a standard midi file either. Tradition is a funny thing in music - we give it an almost holy regard - right up to the second we find something annoying.

But I agree, it is a more than merit able request, most definitely.

:slight_smile:

This isn’t the first time this topic has come up on these forums.
I agree with OP. It’s an issue whenever a beat should not be interpreted as a quarter note in length.
The way I see it, a parameter in Cubase where the user can define the note length of a beat would completely solve this.

EDIT:
Fun fact! The MIDI v1.0 spec does specify SysEx messages for defining notation information such as time signature with number of beats and time signature denominator. It even handles compound signatures.

Yep, it does.
Basically you can if you stay in the score editor, and ignore the piano roll for the most part. But what the OP is suggesting is that the piano roll change to a variably denominated bpm. It seems like such a small thing and yet thats a not small thing to do for an engine and system based on a constant one. It’s more than doable, just that there are numerous timeline ramifications that need to be addressed and in a manner that produces a solution that won’t confuse things for folks. Midi as it is is a known quantity. Midi 1.0 with a variably denominated bpm will never exist, that ship sailed decades ago

A piano roll with a variably denominated bpm may seemingly appear to be midi, but it is no longer a strictly midi based piano roll. That’s quite a big baby to toss out with the bath water by my estimation, but it’s definitely a value judgement for sure, people will differ. It might just boil on down to a traditional engineering calculation of how much effort it would take to implement it vs. how much revenue the change would generate or lose if they don’t implement (how many people of the total demographic does it matter to and how important in the scheme of things is it to them).

Heres what MS copilot has to say about midi tempo.

A MIDI tempo message, specifically called a “Set Tempo” meta message, is a data packet within a MIDI file that defines the tempo of a piece of music by specifying the number of microseconds per quarter note, essentially dictating how fast or slow the music should p
lay; it’s a way to communicate tempo information between MIDI devices or software. [1, 2, 3]

Key points about MIDI tempo messages: [1, 2, 3]

  • Function: This message is used to set the overall tempo of a MIDI sequence. [1, 2, 3]
  • Data format: It is represented as a set of bytes within a MIDI file, with the first byte indicating it’s a meta message, followed by a specific code for “Set Tempo” and then the actual tempo value in microseconds per quarter note. [1, 3, 4]
  • No real-time transmission: Unlike other MIDI messages like “Note On” or “Control Change”, a “Set Tempo” message is generally not sent over MIDI ports in real-time, but rather stored within a MIDI file to be interpreted by a MIDI player. [1, 3, 4]

Generative AI is experimental.

[1] MIDI Set Tempo meta message | RecordingBlogs

[2] https://mido.readthedocs.io/en/stable/files/midi.html

[3] https://majicdesigns.github.io/MD_MIDIFile/page_timing.html

[4] Standard MIDI file format, updated

And for completion, here’s what the MIDI v1.0 specification says about Time Signature (not tempo):

(Source: MIDI 1.0 DETAILED SPECIFICATION)

Awesome.

bb - number of Notated 32nd notes to a MIDI quarter note.

That’s the money quote, right there.

We know in the notation domain 8 32nds will forever equal a quarter note. But here, we have to tell the device exactly it how many midi clocks (ticks) in a beat as well as how many 32nds to a MIDI quarter note. It can now do something with the information to run a metronome or flash a lamp on measure boundaries automatically with no further input.

Since bb is not a constant (of 8) it implies that the whatever a ‘MIDI quarter note’ is, it’s a constant (number of clocks). Thats the rub. Besides, who the heck ever heard of a variable number of 32nds to a quarter? BUT, here we are.

In Cubase, that ‘MIDI quarter note’ is set to usually set to 480 clocks aka PQN. Its a global, you can change to, say 960, no matter.

Very good discussion/topic


Though as has been pointed out above, there’s been some improvement with the new Score Editor.

However if I’m following along correctly, I can imagine this will introduce a layer of frustration for those ‘scoring to picture’ when spotting cues to specific downbeats of measures. There will be a mis-match with what’s marked up in the score, versus what’s displayed in the Key Editor
?

I’m no expert
 maybe I’m not fully appreciating the mechanisms of what’s now being presented with the new score editor, under the hood


I have no means of testing this but the way I read it, setting a time signature of 6/8 would require nn=6, dd=8. I’m not sure what the purpose of the bb parameter is and the spec does not further explain it.

For signatures where the beat is a dotted quarter note e.g., perhaps the cc parameter is the one to be set?

Erm, no? Why would that happen?

Ok, apologies
 will go back and re-read better/slower
 :wink: