Hymns as Transcriptions

Now to the right we see a slightly more elaborate musical score. The staves are numbered in blue for our convenience.

Here is the question: Which staves are to be played by the piano or organ, and which staves are to be sung?

Staves 1 and 2 are for voices, possibly a choir. Staves 3 and 4 are for a keyboard instrument. How do we know this? There are at least two revealing clues:

• TEXT--Staves 1 and 2 have text, and staves 3 and 4 do not. Instrumental music does not usually include text.
• CURLY BRACE (yellow highlight)--Staves 3 and 4 are joined by a curly brace, and staves 1 and 2 are not. Two staves specifically composed for keyboard should be joined by a curly brace.