Solve these clues to fill the grid.
- Personnel who assist their superior in carrying out an assigned task
- 2 Across
- The means whereby some act is accomplished (plural)
- 3 Across
- A ___ that puts the F below middle C on the fourth line of a staff
- 7 Across
- The second lowest adult male singing voice
- 10 Across
- A brass instrument consisting of a long tube whose length can be varied by a U-shaped slide
- 12 Across
- A brass musical instrument with a brilliant tone
- 16 Across
- An alloy of copper and zinc
- 1 Down
- The lowest brass wind instrument
- 4 Down
- Sounds put together in songs and tunes
- 5 Down
- A ___ that puts the G above middle C on the second line of a staff
- 6 Down
- A musical composition for one voice or instrument
- 8 Down
- A customary way of operation or behavior
- 9 Down
- The adult male singing voice above baritone
- 11 Down
- Sound of rapid vibration
- 13 Down
- A brief written record (plural)
- 14 Down
- A mixture of gases required for breathing
- 15 Down