While piano scores are usually not meant for performance outside of study and pleasure (Franz Liszt's concert transcriptions of Beethoven's symphonies being one group of notable exceptions), ballets get the most practical benefit from piano scores because with one or two pianists they allow the ballet to do many rehearsals at a much lower cost, before an orchestra has to be hired for the final rehearsals. Piano scores can also be used to train beginning conductors, who can conduct a pianist playing a piano reduction of a symphony; this is much less costly than conducting a full orchestra. Piano scores of operas do not include separate staves for the vocal parts, but they may add the sung text and stage directions above the music.
while piano scores are usually not meant for performance outside of study and pleasure (franz liszt's concert transcriptions of beethoven's symphonies being one group of notable exceptions) ballets get the most practical benefit from piano scores because with one or two pianists they allow the ballet to do many rehearsals at a much lower cost before an orchestra has to be hired for the final rehearsals piano scores can also be used to train beginning conductors who can conduct a pianist playing a piano reduction of a symphony; this is much less costly than conducting a full orchestra piano scores of operas do not include separate staves for the vocal parts but they may add the sung text and stage directions above the music