I haven’t looked at Iconica yet, but it might be that ‘legato’ is achieved by applying a pedal (CC68, and perhaps even some implementation of the portamento pedal (CC65).
Just because a library calls something ‘legato’, it doesn’t mean that’s really what it is or sounds like in real world translation. In the case of HSO, it simply means the attack phase at the beginning of the sample is really smooth and steady.
For ‘ensemble/tutti section’ sounds in HSO, ‘legato’ is often the ‘only’ sustained articulation for the bowed instruments. If you want sustained passages to get more ‘bite/attack’ then you’d layer in some other stuff on the same channel. Maybe a spiccato or staccato at a much lower relative volume.
Various libraries out there have different ideas on what legato means, and how best to implement it. The various instruments also require different techniques to make it happen. It can get complicated fast…so a few libraries have some ‘scripted options’ (like the legato run in some Hollywood Opus instruments) that might or might not work so well for a given passage (and most certainly might not work well for a polytonal passage such as a violin solo with a lot of double stops). Only way to know is to give it a try.
The ‘expectations’ and technical requirements of achieving legato from an ensemble/section of instruments can be quite different than it is for a solo instrument. Library designers try different things and give us users different options, but in my experience to date, none of them are going to work well in ‘every passage or situation’. So they give us ‘options’ to ‘try’.
Some instruments are truly monotonal. In the real world, you can only play one note at a time. Others, like bowed and plucked strings, you can double stop and get more than one note at a time.
For some libraries achieving ‘legato’ is a ‘pedal’ effect that causes the attack and release phases of the sound to change.
I.E. to simulate changing finger positions with the left hand on a violin, yet the bow movement remains steadily in motion in the right hand. I.E. to change the tongue for a brass instrument from a hard Ta, to a soft Da or La, or not to tongue at all.
As long as it involves one note at a time (mono), then it’s pretty simple to invoke a nice legato using one of the three mainstream methods.
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Use CC68 to trigger a change for the attack phase of a note, perhaps start the sample playing at a later point in time, and as long as the pedal is held, also extend the note-off sustain for several milliseconds.
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Use a keyswitch that effectively does the same thing as the pedal method does above, maybe with some scripts to cycle through a round robin collection of sample layers.
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Do nothing…and have the composer use the regular sustain samples, but the composer simply overlaps the note-on and note-off positions in the sequence until things sound more ‘legato’ (through crossfading). This technique is pretty good until you get passages where the same note repeats in succession (composers have been known to use a second MIDI channel for making general MIDI legato passages that need to repeat the same note often, and will alternate between the channels while overlapping the end of a former note with the start of the present note).
Furthermore, many instruments also involve some portamento when it comes to ‘legato’.
I.E. to do a fast legato passage on a ‘real’ violin, it’s nearly impossible not to have ‘any’ audible portamento throughout an entire passage (one would need to make every subsequent note in the passage come from a different string to achieve it…and then again, that technique still has its own unique sound that no sample library I know of attempts to duplicate at this time [a complete chromatic set of samples for every string that the user can pick on demand]).
Most libraries are still not using enhanced abilities of Note Expression or MPE, but instead use traditional MIDI and CC events to ‘play’ the instrument. I.E. CC11 can control expression volume, but it will be applied to ALL NOTES sounding on the same channel at the same time. If a legato (CC68), portamento (CC65), or sustain (CC68)pedal is applied, it goes for ALL notes sounding on the channel at the same time. For this reason, many solo instruments go into a true mono mode where it’s not possible to play more than one note at a time. If you play a second key while a first one is already down, you get a ‘smooth’ note change, and for many instruments some portamento is automatically applied.
All this means it’s pretty difficult to implement a ‘polytonal’ legato for a given instrument, over a single channel that wouldn’t drive CPU usage considerably higher, and perhaps also require some kind of ‘pre roll’ action to see a bar or so ahead into the music to do some kind of ‘analysis’ and make choices.
Now, some libraries might offer access to a lot of different sample layers where the attack and release phases are altered in order to better simulate playing legato for specific instruments or families of instruments, and they might also allow playing more than one note at a time on a channel; however, unless the instrument is using a more advanced sequencer with note expression or something similar, there’s no way to get portamento and crossfading effects working properly if the instrument is in a ‘polytonal’ mode.
So, even if a library shows you something named ‘legato’, it’s probably not TRUE legato (portamento and potential scripted crossfading effects invoked) unless the track is in a ‘mono’ mode.
In the case of HSO, it applies to ‘tutti or ensemble’ programs/patches. It just means you get a ‘string section sustain’ with a very ‘subtle’ attack phase to the sample. In HSO, if you want sustains with more punch/bite, then you’ll have to ‘layer it up’ with an ensemble spiccato.
As for the ‘poly legato’ mode provided by some libraries…
Most likely all that is doing is disabling the portamento aspect of things, and changing the attack/release phases of the loaded instrument.
Again, I haven’t had a chance to take Iconica for a test drive, but I suspect it’s possible to make it do something similar. Especially if you have a full HALion at hand.
