[19]
[quotePost id=19067]If you have a MIDI File with data spanning multiple Groups. Then you should include a Set Tempo message for each of those Groups.[/quotePost]
Perhaps that should be stated more clearly in the specs.

What will be the duration of the following file? One second or half second?

-- dcs = 0

-- dctpq = 96, group 1

-- tempo = 120 BPM, group 1

-- dcs = 0 // do we need dcs when setting tempo for multiple groups?

-- dctpq = 96, group 2

-- tempo = 60 BPM, group 2



-- dcs=0

-- start clip

-- tempo = 120 BPM, group 1

-- time sig = 4/4, group 1

-- dcs = 0 // do we need dcs when setting tempo for multiple groups?

-- tempo = 60 BPM, group 2

-- time sig = 4/4, group 2

-- dcs = 0

-- note on, group 1

-- dcs = 0

-- note on, group 2

-- dcs = 96 // a quarter note = 0.5s or 1s?

-- note off, group 1

-- dcs = 0

-- note off, group 2

-- dcs = 0

-- end clip

[quotePost id=19067]Yes, Set Tempo is per Group. If you have a MIDI File with data spanning multiple Groups. Then you should include a Set Tempo message for each of those Groups.[/quotePost]
Are all groups required to have the same tempo? Or can they be different?

If they can be different the DCS messages become a complicated topic (see Sema's example file). The DCS message uses the current tempo but it's not per-group.

[20] Giel's example raises another question , Is it allowed to have multiple configuration headers in a clip file ? The MIDI spec talks about "a configuration header" following the file signature. if not, how to define the ts & tempo for each group ?

Could you let me know if the other open questions, I should go back to read the spec (RTM) 🙂 or they are valid questions ?
I have opened a discord with forums so that topics can be discussed in a manageable manner. This tool would be great to manage topics, (not only specifications)
Slack would be another alternative

https://discord.gg/Nk289NR4KK