The Blank Instrument

General discussion about tracking, help and support.
User avatar
Posts: 52
Joined: Wed Sep 02, 2015 4:31 pm
Location: Nashville, TN

The Blank Instrument

Postby epic1sound » Mon May 16, 2016 7:16 pm

Might be a stupid question but what does a "Blank" instrument refer to? In most instrument sets I've seen there is always one but there's no volume envelope or any other setting. How does generate sound without a volume envelope and/or what's the purpose of having it?

Last edited by epic1sound on Mon May 16, 2016 8:06 pm, edited 2 times in total.
Famitracker on a Mac... It's possible because I do it.

Andy P. Scott

User avatar
Posts: 933
Joined: Mon Apr 20, 2015 8:47 pm
Location: Trapped in a 2A03

Re: Blank Instrument

Postby MiniMacro » Mon May 16, 2016 7:38 pm

wow this is total BS
you can see my beautiful music there~

User avatar
Posts: 199
Joined: Tue Apr 21, 2015 3:24 am

Re: The Blank Instrument

Postby jaxcheese » Mon May 16, 2016 9:03 pm

I'd say it's primarily used for the triangle channel (which doesn't do anything with volume envelopes, really), or if you want to handle duty/volume with effects rather than envelopes.
Fan of:
Cave Story, Mega Man X, MOTHER 3, Star Fox 64, Super Metroid, Shining Force.
Classic SEGA, Treasure, Square, Falcom.
Various roguelike RPGs and shmups/bullet hells.

User avatar
Posts: 236
Joined: Sun Sep 20, 2015 10:13 am
Location: Scotland

Re: The Blank Instrument

Postby drdevil » Mon May 16, 2016 9:43 pm

I've also seen the blank instrument being used for DPCM; sometimes the instrument is titled "Blank/DPCM", from what I've observed.

User avatar
Posts: 378
Joined: Sun Apr 26, 2015 7:46 pm

Re: The Blank Instrument

Postby Stratelier » Tue May 17, 2016 1:09 am

The blank instrument is simply that - no volume envelopes, no arpeggios or duty cycles, and that's the whole point.

This is because instrument definitions tend to override certain effects -- i.e. you can't use the Vxx effect on an instrument with a custom duty cycle, you can't (always) use note slides on an instrument with a custom arpeggio. The blank instrument is as close as you can get to simply setting the 2A03's pitch registers directly, and there's still a lot you can do with that.

Of course, since volume envelopes are the most common feature of instruments, the blank instrument tends to be put on Triangle duty (since no volume control there). It also doubles as a convenient place to store DPCM samples.

User avatar
Posts: 475
Joined: Thu Apr 23, 2015 7:39 pm
Location: Hong Kong SAR

Re: The Blank Instrument

Postby HertzDevil » Tue May 17, 2016 8:12 am

Anywhere whenever pattern effect commands are used to articulate notes as a whole, so that instrument definitions are represented entirely as effect commands.

If a sequence instrument with some blank sequences is used, not necessarily all of them, then new note triggers behave as if the following sequences are defined respectively:

  • Volume: { 15 } (on FDS, 31, instead of 32)
  • Arpeggio: { }
  • Pitch: { 0 } (relative)
  • Hi-pitch: { 0 }
  • Duty: { }
  • N163 Wave: { }, but { 0 } on switching to a new instrument index
Some so-called blank instruments actually contain a volume sequence beginning with { / 15 } so that it may share the same volume sequence with other instruments.

If a blank instrument appears on its own without triggering a note, all sequences are halted at that point.

By definition, a VRC7 instrument cannot be blank, although it may contain a custom patch that makes no sound. Similarly, any N163 instrument must contain at least one waveform.

Stratelier wrote:you can't use the Vxx effect on an instrument with a custom duty cycle.

You can use Vxx commands as long as the current duty / wave sequence has finished, and the same goes for arpeggio and the family of slide effects. Thus, at standard speed these patterns are possible, and equivalent in this case:

Code: Select all

       # Pulse 1        Pulse 2
ROW 00 : C-3 00 . ... | C-3 01 . ...
ROW 01 : ... .. . ... | === .. . G05
ROW 02 : ... .. . V02 | ... .. . ...
Given instrument 00 uses { 1 0 } as its duty sequence, and 01 uses { 1 / 0 2 }. A Vxx command updates both the current duty and the default duty at the same time, whereas instrument duty sequences are processed after that.
refactoring 0cc-famitracker

User avatar
Forum Staff
Posts: 50
Joined: Mon Apr 27, 2015 8:14 pm
Location: Lawrenceville, GA

Re: The Blank Instrument

Postby RushJet1 » Tue May 17, 2016 12:26 pm

I've written a few ftms that only use a blank instrument. It can make some stuff simpler but sometimes you end up having to do crazy stuff to compensate for the lack of instruments (which I end up doing here a bit).
(174.66 KiB) Downloaded 118 times

User avatar
Posts: 241
Joined: Fri May 15, 2015 1:37 am
Location: Nanamori-Chuu

Re: The Blank Instrument

Postby w7n » Wed May 18, 2016 5:18 am

RushJet1 wrote:I've written a few ftms that only use a blank instrument. It can make some stuff simpler but sometimes you end up having to do crazy stuff to compensate for the lack of instruments (which I end up doing here a bit).

I've got used to covering in speed 1 and using mainly blank instruments for pulse & saw channels. It all started when I made my first Famicaloid module, but then I have come to like the idea of having full control of every single frame. under reconstruction, better player might be available in the future.

VRC6 PWM is GAY because it has colours of the rainbow in the NSFPlay keyboard visualizer.