4/4 to 6/8 beat

I have played first version style a 6/8 rhythm in 180 BPM tempo, the same rhythm style is played in the second version but this time in 4/4 at 104 BPM, What would be the right tempo for the second version to match exactly the first version? So i can export the second version and import it in the first version ( 6/8, 180 BPM ).
Many thanks.


Does MusicCalc help?

Many thanks, but I’m afraid no.

I’m not really sure, what you’re trying to match.
If you want 1 bar of 6/8 to be the same length of 1 bar in 4/4, you can calculate:
6/8 at 180 bpm = 3 beats per second => 1 bar is 2 seconds
2 second bars in 4/4 => 2 beats per second = 120 bpm

if this is what you’re trying to do, maybe I didn’t get it though.


When I used the MusicCalc, it also returned me 120BPM. And from my (poor) math, I would also say it.

I recorded a rhythm called “Hewa” 6/8 180BPM in my (x library sounds), the same rhythm “Hewa” has someone recorded in another library sounds but they recorded in 4/4 104BPM, because there library sounds much better than my, I want to import there rhythm in my already finished song. But don’t now how to let their rhythm sync with my rhythm.

I’m guessing you understand the difference between duple and compound time(?) but just in case:-

4/4 means there are four crotchet beats to each bar. The main stress is on beat 1. There is a smaller stress on beat 3 and beats 2 and 4 are weakly stressed.

6/8 means there are six quaver beats to a bar. The main stress is on beat 1. There is another stress on beat 4. All other beats are weakly stressed.

Consequently, 6/8 is more like 2/4. Indeed, a 6/8 bar can be written in 2/4 using two groups of triplet quavers.

TWO bars of 6/8 could be written as ONE bar of 4/4 (though they would sound different rhythmically in performance). The difference is subtle but it’s there.

When conducting 6/8 it is sometimes convenient and easier for the orchestra to read if it is done as TWO dotted crotchet beats to a bar with each beat divided into THREE quaver “sub-beats”, 1 2 3 2 2 3… This is different to 2/4 time which is also TWO crotchet beats. 1 2 2 2 1 2… If it is necessary to divide this beat, it will be divided into TWO quavers.

Hence 2/4 (and 4/4) are simple duple time whilst 6/8 is compound duple time. They feel thymically very different. The beat unit in simple duple time is the crotchet, the beat unit in compound duple time is the dotted crotchet.

Note when doing the maths that 6 quaver beats per bar is NOT the same as 3 crotchet beats per bar (which is 3/4); rather it is equivalent to 2 dotted crotchet beats per bar (as above).

You’re amazing man, many thanks for your time and information.