Full Song Guide Tracks (extended Dendy technique)
TLDR: sample start param’s 1-100 actually maps to 128 values (a byte). Trim your audio to a whole number of bars. Make an Obsidian with the guide loaded as a sample. Make a part of exactly the length of the guide. Fill that part with 128 equal length notes (which may be rather odd lengths, but as long as they fill 100-101% of the part, it works)
The Extended Dendy Technique
In our band we use NS1 and now NS2 to compose backing tracks to complement our songs. Typically, I was doing this in rehearsal with band present, but this can waste time and it generally preferable for us to record and then compose without another 4 people standing around waiting. This leads to the requirement for NS1/2 to be able to playback a guide track for which to compose.
Inspired by a comment from Dendy which I now can’t find (someone please link it if you can find it) in which he describes using an Obsidian synth, with sample start automated to scale from 0 to 100 over a part matching a loaded sample audio file, allowing it to be used a bit like an audio track. It works! Kind of...
To do this for a full song track, it’s taken me some hours of experimentation and pain to arrive at, hopefully, an applicable solution. Firstly, I was confused about the actual values tracked by a linear automation line on a part. Naively drawing a line from 0 at part beginning to 100 at part end, with N notes triggering the sample did not always yield effective results. It would sometimes skip/jump, replaying fragments of the audio. In many attempts it would sound fine, but when the click was turned on (we’d recorded with click), a subtle drift was apparent, with the track gradually becoming late relative to the click.
A short experiment with a default Obsidian, coarse pitch mapped to knob 3, knob 3 automated from 0 at start of bar 1 to 100 at end of bar 128 will reveal that the 1 to 100 values you can directly manipulate, in fact map to a single byte value: 1 - 128. If you make a part of 128 bars/beats/whatever, or some divisible of that (64, 256 etc) the coarse pitch changes triggered by the automation will coincide with bars/half bars/beats/whatever.
Ok. Keep it simple, right? I tried taking a 128 bar segment of the guide and triggering 128 bar-long notes in a 128 bar long part, with the automated sample start 0-100 as before. You’d think it’d work... no. It drifts late. The track falls behind the click. After many attempts I found that if you trimmed the audio to 129bars + 1beat (assuming 4/4) then, somehow, it stayed pretty much in sync with the click. This is not how I want to work though and feels arbitrary, like a song at a different tempo will need some other weird “extra” bit.
There has to be better way and there is, I think. Somehow, editing the audio to be a quantised number of bars and making a part with 128 equals notes, the last of which ends at or just past the end of the containing part, yielded a solid result, locked in with the click. Getting initial note length right (2.67 beats, ok?) can be a faff but once it’s done, you can have a 4 minute song playing in the background, with reasonably usable subdivision, i.e. “let’s loop the chorus and see if it works”. I believe there’s needs to be a suitable relationship between the note events and the uptick of sample start coming from the automation, such that the note events happen a little after the next of the automation 128 values has been tripped.
I don’t quite know why or what’s going on. I feel the simple 128 bar version should work, but it really doesn’t. Any input very welcome on this. At least I do have a working version for now. I really can’t wait for true audio tracks