The four crossword solutions for the term 'QUICKLY, IN MUSIC' are ALLEGRO (7 letters), PRESTO (6 letters), Mosso (5 letters), and Subito (6 letters). ALLEGRO is an Italian musical term meaning 'quickly and bright' and is usually played at a moderately fast tempo. PRESTO is another Italian term meaning 'very quickly' and is usually played at a very fast tempo. Mosso is an Italian term meaning 'AGITATED' and is usually played at a moderately fast tempo. Finally, Subito is an Italian term meaning 'SUDDENLY' and is usually played at a very fast tempo.