Message
Re: [disklavier] A reply to your message.
2004-01-04 by PianoBench@aol.com
In a message dated 1/3/04 1:18:54 PM, Spencer writes:
On thing that is very confusing is that people seem to be using
channel and track interchangeably even within the same sentence and it
is difficult to figure out what they mean.
Although I can't comment on how any one person uses these terms, I think that I can clear up some of the confusion that many people associated with these terms.
It's best to start by thinking of the manner in which MIDI data is sent from a computer sequencer to a MIDI instrument using a single MIDI cable. The MIDI file that is loaded into the computer sequencer can--theoretically--have an unlimited number of tracks. However, the single MIDI cable that joins the computer and the MIDI instrument can carry only 16 channels of information. Therefore, each of those unlimited number of tracks must be assigned to one of the 16 available MIDI channels.
These 16 MIDI channels function as though there are 16 separate data cables. The receiving MIDI instrument functions as though it is really 16 separate instruments, each connected to one of these fictional 16 data cables.
The result of this 16 channel scheme is that--in most cases--there is little point in considering the possibility of having more than 16 tracks of data. If you have 20 tracks, for example, those 20 tracks still must be funnelled down into the 16 available channels.
The reason that some people might create a MIDI file with more than 16 tracks is that it is often easier to keep certain parts separate during the recording and editing process. For example, you might have 5 different tracks for orchestral strings: 1st violins, 2nd violins, violas, cellos, and basses. However, if you end up using the same string patch for each of these tracks, you might as well assign all of these tracks to the same MIDI channel, such as channel 5.
This channel/track situation becomes a bit more confused when it comes time to save a Standard MIDI File. There are two SMF types to consider: Type 0 and Type 1. Modern Disklaviers will play both types but will only record Type 0. Most published MIDI files are Type 0, but there are plenty of Type 1 files on the Internet.
A Type 0 SMF technically has just a single track. HOWEVER, that single track knows the MIDI channel assignment of every single event. When you open a Type 0 SMF in a computer sequencer, the sequencer looks at allof the channel data and splits that data into separate tracks. The result is that you see anywhere from 1 to 16 tracks, each hardwired to the corresponding MIDI channel.
For all practical purposes, you can think of a Type 0 SMF as a MIDI file with anywhere from 1 to 16 tracks, each hardwired to the corresponding MIDI channel.
A Type 1 SMF can have an unlimited number of tracks, each of which is assigned to any of the 16 MIDI channels.
Regards,
PianoBench