Marlboro Music was conceived as a retreat where young musicians could collaborate and learn alongside master artists in an environment removed from the pressures of performance deadlines or recording.

But it was Busch, writes biographer Tully Potter, who provided the first impetus, as he "had long wanted to create an environment in which professional players and rank amateurs could make music together, studying the chamber literature in depth and giving concerts only when and if they wished to do so."

"[6] Marlboro's purpose moved away from Busch's idea of amateur participation; instead leading professionals from both solo and orchestral positions work with young musicians of the highest promise and achievement, who must pass through a rigorous audition process to be accepted.

Prominent musicians associated with Marlboro have included Pierre-Laurent Aimard, Emanuel Ax, Joshua Bell, Jonathan Biss, Anner Bylsma, Pablo Casals, Nikki Chooi, Jeremy Denk, Leon Fleisher, Gary Graffman, Hilary Hahn, Mieczysław Horszowski, Gilbert Kalish, Anton Kuerti, Lang Lang, James Levine, Yo-Yo Ma, Mischa Maisky, Viktoria Mullova, Siegfried Palm, Murray Perahia, Lara St. John, Richard Stoltzman, and Sándor Végh.

A tradition Serkin began of ending the summer with a performance of the Beethoven Choral Fantasy – in which most participants, even non-singers, joined in the chorus – was discontinued with his death in 1991, but was reinstated a few years later.