What's the name for when you write multiple voices on same staff? And are there any cons?

1. What are multiple voices in music?
2. What is the name of both staffs combined?
3. What does 2 part voices and piano mean?

What are multiple voices in music?

polyphony. A type of musical texture where two or more independent parts (or voices) retain their individual integrity while combining into a coherent musical unity.

What is the name of both staffs combined?

The Grand Staff. The grand staff (or “great stave” as it's called in Britain), is a combination of two staves put together, usually a treble clef and a bass clef.

What does 2 part voices and piano mean?

Two part writing occurs when one staff is used for two different instruments, voices, or melody/harmony lines. ... Composers seem to enjoy challenging students with some two part writing in their compositions.