Tchaikovsky - Cello Concerto, TH 249 (Piano Reduction and Solo Part)

Tchaikovsky left 60 bars of a cello concerto among his Pathetique Symphony sketches. In 2006, Yuriy Leonovich orchestrated the sketch and fleshed the piece out into a 30-minute cello concerto. Leonovich wrote an article about his writing process for Tchaikovsky Research: http://en.tchaikovsky-research.net/pages/Talk:Cello_Concerto