Crossword Genius

This composer's phone may be found in the band (5)

Ross

I believe the answer is:

sousa

'this composer's' is the definition.
(I've seen this before)

I cannot understand how the remainder of the clue works.

(Other definitions for sousa that I've seen before include "he produced the Washington Post" , "John Philip ..., composer of military marches" , "US composer of marches" , "John Philip -, composer of famous marches (The Stars and Stripes for Ever)" , "Composer of "The Stars and Stripes Forever"" .)

I've seen this clue in The Guardian.
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