Channels and Tracks

[Normanfernandez]

Not too long ago, someone posted.
A Explanation on Channel and Tracks.

That a Style has 16 tracks
And Midi song has 32

What's the difference between Tracks and Channel??

[Joe H]

Norman,

MIDI has only 16 channels. Old style sequencers, like the audio tracks in a DAW had up to 60 MIDI tracks to record on.

The style files have 16 channels all on one track.  This is called a Type 0 MIDI file. We can see only 8 channels for the 8 style Parts. That is why Yamaha chose to call the MIDI channels "Parts".

Since there is only 16 MIDI channels in all. Song files have 16 channels also, but there can be 2 MIDI buses in the keyboard (in effect 2 tone generators each with 16 channels) that offer 32 channels.  I don't play MIDI song files very much so I don't know how that works on arranger keyboards.  But any instrument that has a MIDI In A and a MIDI In B can support 32 MIDI channels. The way that works is if you have a sequencer from a computer with Type 1 files and a Port A and a Port B... you can assign the tracks to either Port A or B.

The Multi Pad player is a MIDI Type 1 file.  It has only 4 channels, but each Pad is on a separate track.  Then there is a 5th "track" that contains MIDI messages.  Type 1 is an old format that was used in the early days of MIDI.  We could record on separate tracks like a tape recorder.  Each track could be assigned a MIDI channel.  If we wanted to add some additional controller messages later on, we could record them on a separate track and select the MIDI channel.

Things were done this way because there were no graphic editors like there are today where you can filter selected data such as notes to display, or MIDI controllers to display only.  So... it was easier to edit a song file in the old days if notes were on one track and controller messages were on another track.

Then there was the possibility of with most sequencers of separating individual drum notes on separate tracks for editing purposes.  It was much easier to edit (change) individual drum notes if all like-notes were on a separate track.  But with modern graphic editors this is no longer necessary.

[Toril S]

Thanks Joe H!

[Normanfernandez]

Type 1 files contain separate information for each track. For a Type 0 file, however, all the tracks are merged into a single track, although MIDI channel information is still retained. When a Type 0 file is loaded into a sequencer, it will take each channel's information and put it on a separate track.


Is channel 10
Midi type 1??

What am I getting wrong here?

[SeaGtGruff]

Neither channel 10, nor any other MIDI channel, has a MIDI type-- that is a characteristic of MIDI files.

Standard MIDI files (or SMFs) come in three different types or formats-- format 0 (or type 0), format 1, and format 2. The difference between these three formats has to do with how many tracks the file has and how the tracks are intended to be played.

Note that for this discussion, "track" specifically refers to a "track chunk" in a MIDI file. MIDI files are divided into portions called "chunks" (that is, chunks or blocks of data), and the specifications for standard MIDI files defines two such types of chunks-- a header chunk, which contains a Chunk ID of "MThd"; and a track chunk, which contains a Chunk ID of "MTrk." There are other types of data chunks that can appear in MIDI files-- such as the "CASM" chunk of a Yamaha style file-- but they are not defined by the standard MIDI file specifications; rather, they are proprietary chunks defined by the companies that use them.

Format 0 SMFs have one and only one track chunk. The file can use more than one MIDI channel-- up to 16 MIDI channels per MIDI port-- but the messages for all of the channels that are used by the file must be contained within that one "MTrk" chunk.

Format 1 SMFs have more than one track chunk-- it can be two, three, four, or some other number of track chunks, but it must be more than one (otherwise the SMF would be a format 0 SMF).

Format 2 SMFs also have more than one track chunk, just like format 1 SMFs, but they are played back in a different fashion:

The tracks of a format 1 SMF are intended to be played back simultaneously, like multiple tracks of a song which are played back in unison to create the song.

But the tracks of a format 2 SMF are intended to be played back separately, like multiple tracks of an album or CD which are played back individually. The tracks of a format 2 SMF can be complete songs, or they can be simple rhythmic patterns or melodic phrases which are not complete songs in and of themselves.

Your Yamaha keyboard can play back either format 0 or format 1 SMFs, but it cannot use format 2 SMFs. However, when you record a MIDI song file on your Yamaha keyboard it will be recorded as a format 0 SMF. (Some Yamaha models-- such as the PSR-E models-- actually record their User Songs to multiple "MTrk" chunks, similar to a format 1 SMF, but there are no corresponding "MThd" chunks for the User Songs, so they are not SMFs per se; and when you convert the User Songs to SMFs using the "Save SMF" option in the keyboard's File Control menu, the SMF is written as a format 0 SMF.)

When you load or import a format 0 SMF into a DAW, the DAW may keep all of the data together as a single MIDI track, or it may split the data up into multiple MIDI tracks based upon the MIDI channels of the messages.

For example, Cubase will import a format 0 SMF into a single MIDI track, which is very confusing if you don't understand what is happening, since it can appear as though all of the channels were merged into one channel-- but that isn't the case, since all of the channel messages still retain their internal channel numbers, just as they do within the single "MTrk" chunk of a format 0 SMF.

Fortunately, Cubase has a "dissolve" function which can be used to separate the various MIDI messages into multiple MIDI tracks based on some criteria, such as their channel numbers.

Depending on the parameters you use with it, this same "dissolve" function can also be used to separate MIDI messages into multiple MIDI tracks based on their Note numbers. This is especially useful if you want to separate the Note events in a "drum channel" into different tracks based on their percussion sounds. For example, you could dissolve all of the bass drum Note events to one track, dissolve all of the snare drum Note events to another track, dissolve all of the cymbal Note events to yet another track, etc.

[pjd]

Michael gave a bit of a computer science explanation for track vs. channel, which I love.

I'm going to offer an explanation from the user point of view.

An arranger keyboard that plays styles or songs is split into two parts:

         Sequencer    ----------------->    Tone generator
                        MIDI messages

The sequencer sends MIDI messages to the (multi-timbral) tone generator.

"Channel" is a MIDI concept. "Track", or the word "Part", is a sequencer concept.

The tone generator is 16 voice multi-timbral meaning it can sound notes for up to 16 different instruments. Each instrument is on a MIDI channel. The MIDI channel number in a MIDI Note ON message (or whatever) tells a particular instrument what to play.

A sequencer track is a way to organize MIDI notes, etc. (A track is a container.)  In one scenario, all of the messages in a track are for the same MIDI channel. This is where and why folks tend to conflate "track" and "channel." In an equally valid scenario, a track can contain messages for multiple MIDI channels.

Michael's explanation gets into Standard MIDI File (SMF) format. SMF is a sequencer thing -- a convention for organizing MIDI messages by track(s).

Hope this helps.

-- pj