An important part of Franz Liszt's work is his treatment of other composers' music. He often wrote piano transcriptions, arrangements and orchestrations under various titles/genres, of other people's music. 12 Lieder von Franz Schubert, S. 558 is a collection of 12 songs, listed as S. 558 on Liszt catalogue, originally written by Franz Schubert and adapted for solo piano by Liszt. This selection (sometimes catalogued as as LW.A42) was conceived in 1837, and revised in 1876. It was dedicated to the countess of Aragon, and it included a version of Schubert's famous Ave Maria.