transposing instrument

22 LETTERS · STARTS WITH T

transposing instrument is a valid 22-letter word worth 26 points in Scrabble and 34 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

T1R1A1N1S1P3O1S1I1N1G2I1N1S1T1R1U1M3E1N1T1

1 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 2 + 0 + 1 + 1 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 1 =26 PTS

DOUBLE WORD → 52TRIPLE WORD → 78

MEANING

What does transposing instrument mean?