MENDELSSOHN swore off them permanently. Debussy called them “a purely arbitrary affair.” Bartok said they were for horses, not musicians. The charges against classical music competitions are familiar: art is not a sport; the need for jury consensus rewards conformism; fear of losing stifles innovation; actual losing can cripple morale and, potentially, a career.

But several new endeavors challenge these complaints by tweaking the competition concept and using the Internet to create an open dialogue among composers, performers and the public.

On Nov. 15 the violinist Hilary Hahn announced the Hilary Hahn Encore Contest in a YouTube video. Until mid-March anyone may submit a short piece for violin and piano, and Ms. Hahn will perform and record the winner alongside 26 other encores she has already commissioned. Contestants enter by uploading a PDF of a score and a MIDI sound file to Ms. Hahn’s Web site (hilaryhahn.com).

The same day the composer David Lang, a co-founder of Bang on a Can and a Pulitzer Prize winner, announced a similarly crowd-sourced competition. In conjunction with a new CD of Mr. Lang’s piano works, entrants could download a free score of his short piece “wed” and post their own performances on YouTube until Dec. 31. The winner will be flown to New York to play in a concert of Mr. Lang’s music at Le Poisson Rouge in May.