"Parameter maps, in GS, "master tune" is four bytes at address 40 00 00, and "master volume" is one byte at address 40 00 04. They could be set with two separate data set commands:
F0 41 10 42 12 40 00 00 tt tt tt tt ss F7
F0 41 10 42 12 40 00 04 vv ss F7
But it is also possible to combine them:
F0 41 10 42 12 40 00 00 tt tt tt tt vv ss F7"
see conversation:
https://www.midi.org/forum/request-for-comment-midi-implementation-schema
"Parameter maps, in GS, "master tune" is four bytes at address 40 00 00, and "master volume" is one byte at address 40 00 04. They could be set with two separate data set commands:
F0 41 10 42 12 40 00 00 tt tt tt tt ss F7
F0 41 10 42 12 40 00 04 vv ss F7
But it is also possible to combine them:
F0 41 10 42 12 40 00 00 tt tt tt tt vv ss F7"
see conversation:
https://www.midi.org/forum/request-for-comment-midi-implementation-schema