I've been listening today to Britten's Sinfonietta, op. 1, written when
the composer was 18 or 19. Of course, Britten had written other non-opused
pieces previously, but nevertheless it shows a real virtuosity of both form
and orchestration, despite its obvious debts to Mahler, Schoenberg, and
Stravinsky. I began to think of other op. 1s, particularly Nielsen's
Little Suite for Strings, a delightful work which shows Nielsen's mastery
of string writing from apparently the get-go.
I propose a thread of really good op. 1s. Talk about your favorites!