*Dmitry Shostakovich - 2 Pieces for String Octet, Op. 11

*Felix Mendelssohn - String Octet in E-Flat Major, Op. 20, MWV R20 

OR
*Wolfgang Amadeus Mozart - Sinfonia concertante in E-Flat Major, K. 364(sextet version) 

*George Enescu - String Octet in C Major, Op. 7