Op. 123

In music, Op. 123 stands for Opus number 123. Compositions that are assigned this number include:


 * Beethoven – Missa solemnis
 * Ries – Piano Concerto No. 6
 * Saint-Saëns – Cello Sonata No. 2
 * Schumann – Festival overture on the Rheinweinlied for orchestra and chorus