How many letters does the top answer for “composer of the big bang theory” have?

The most common answer is lorre (5 letters).

Crossword clue: composer of the big bang theory

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

lorre 5 letters wd-fact-v3

United States actor (born in Hungary) noted for playing sinister roles (1904-1964)

author of the big bang theory 60% similar → bialik

director of the big bang theory 60% similar → bialik, gilbert, lorre

wrote the big bang theory 60% similar → bialik