How many letters does the top answer for “author of symphony no. 1” have?

The most common answer is schumann (8 letters).

Crossword clue: author of symphony no. 1

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

schumann 8 letters wd-fact-v3

German romantic composer known for piano music and songs (1810-1856)

shostakovich 12 letters wd-fact-v3

Russian composer best known for his fifteen symphonies (1906-1975)

author of symphony no. 3 100% similar → bernstein, mendelssohn

author of symphony no. 4 100% similar → williams

author of symphony no. 6 100% similar → tchaikovsky

author of dante symphony 50% similar → liszt

composer of symphony no. 1 50% similar → brahms, bruckner, elgar

composer of symphony no. 100 50% similar → haydn

composer of symphony no. 3 50% similar → bernstein, gorecki, mendelssohn

composer of symphony no. 40 50% similar → mozart