I’m writing a passage for a 5-line percussion staff that includes both a bass drum and clash cymbals. I know to write each instrument in its own voice, and this is what I have currently [written in Sibelius]:
As you can see, the bass drum is written in the 1st voice (dark blue) up to Bar 82, as it’s the only instrument in the staff until that point. Then Bar 82 introduces the clash cymbals, so I switch the bass drum to the 2nd voice (dark green) and the cymbals to the 1st voice. This continues on until the end of the passage with the cymbals, at which point I put the bass drum back in the 1st voice.
So here’s my question, in two parts:
A) When you have a staff with two (or more) instruments on it, does each instrument stay in its own voice (1st, 2nd, 3rd, so on) throughout the entire piece, or can an instrument switch between voices depending on whether other instruments are present in the phrase/passage?
B) If you can switch voices, do you determine which instruments stay in which voice according the the phrase, or can you do it on a bar-by-bar basis? For instance, in the below pic, Bar 83 has no cymbals and only a bass drum, so I switched the bass drum back to the 1st voice for that bar, before switching back for Bar 84, which has cymbals again. Is this proper?
Please let me know if any of this is unclear. Thanks to anyone who replies.