Listen to Cello Concerto No. 1 in E-Flat Major, Op. 107: I. Allegretto online. Cello Concerto No. 1 in E-Flat Major, Op. 107: I. Allegretto is an Instrumental language song and is sung by Mstislav Rostropovich, David Oistrakh and Moscow Conservatory Symphony Orchestra. Cello Concerto No. 1 in E-Flat Major, Op. 107: I. Allegretto, from the album Young Slava, was released in the year 2017. The duration of the song is 6:03. Download Instrumental songs online from JioSaavn.