How many letters does the top answer for “composer of rhapsody in blue” have?

The most common answer is gershwin (8 letters).

Crossword clue: composer of rhapsody in blue

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

gershwin 8 letters wd-fact-v3

United States composer who incorporated jazz into classical forms and composed scores for musical comedies (1898-1937)

composer of blue 67% similar → mitchell

composer of blue banisters 50% similar → rey

composer of blue velvet 50% similar → badalamenti, lynch

composer of bohemian rhapsody 50% similar → baker, mercury

composer of the blue danube 50% similar → strauss