Subject: Re: [linux-audio-dev] News about sequencers (not my own though!)
From: Fredrik (aeonek_AT_home.se)
Date: ti tammi 18 2000 - 21:22:04 EST
> Logic's one is kind of cute, but not too extensible.
Well i find it more extensible than Cubase. I haven't played with CW much, so i can't make any comparisions there... But they all seem to use the same basic concepts, with "arrange" and "piano roll" editors.
> Right... the idea is that in PEGS, you as the user get to choose
> what spikes represent what properties, so this is definitely
> possible. However, if the asterisk on the right was not meant to
> be a separate event, but rather just an artifact of drawing in ASCII,
> I'm afraid that PEGS in its current design doesn't handle that.
But the asterisk on the right *is* a separate event. MIDI has no concept of "note-duration", it's just "note-on" and "note-off". The line drawn between the too in common piano roll editors is just for convinence.
>
> | e = duration
> | / n = attack velocity
> |/ s = attack rate
> *----------- ne = release velocity
> |\ se = release rate
> |
>
Does MIDI handle this? I thought that the only event-specific properties was note-on velocity and note-off velocity. Besides that, there's CC's, which are channel-specific, and polyphonic aftertouch, which is note-specific.
I would think it would make more sense to put release rate and velocity *at the end* where it's actually happening. Obviously, you don't represent note-off as an event, but in the note-on as "duration". If you wanted, you could put an "event-dot" at the end of the duration spike, and have the properties associated with note-off represented as spikes on that dot.
> > Contiguous events like modulation and aftertouch are a bit harder.
> > Especially event-specific ones like polyphonic aftertouch.
>
> In this sense, PEGS inherently takes a pretty low-level viewpoint:
> each value change for the mod wheel is a separate event and is
> graphed as such, just like in raw MIDI. You can, however, define
> meta-style events which don't exist in raw MIDI, such as "ramp
> modulation amount from 0 to 127 over 8 measures". You could
> alternatively provide a pen callback that treats "continuous"
> controllers semi-intelligently, in the manner of the line drawing
> tool in Cakewalk's controller editor.
But CC events are different from note events, in that they don't have a pitch value. So if you have pitch associated with the y-value, where do you put CC events? Polyphonic aftertouch does have a pitch value, so that's easier.
In your meta-events, can you bind event properties to meta-parameters? Like "ramp modulation amount from current value to whatever the North spike specifies over whatever the duration spike specifies". This would make CC programming real easy.
A nice idea would be to have macro events, that represented a short midi sequence as a single event. You could use this to do recycle-style drum programming, although in pure MIDI.
> These are somewhat advanced examples of ways to customize PEGS,
> and I wouldn't expect users to be able to do them without both
> documentation and examples. That's a big part of the reason I've
> been saying that 1.0.0 is a long way off. I can probably
> (hopefully) have the actual core of PEGS completed fairly soon,
> but it could take another few months after that before I can come
> up with enough default callbacks for it to be at all useful for
> end-users.
>
> Div.
>
I'm looking forward to a release. It seems that the interesting part of your project is the UI, and it's an area where i think current sequencers are lacking. I grew up on trackers, where you have precise control over every parameter at every time. Sequencers are built on the assumption that you specify parameter changes beforehand in the synth, with EG's and LFO's, and just trigger those with a simple "play note at pitch X and velocity Y now"-event. I'd like to see some new ideas.
/Fredrik
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