https://outhere-music.com/en/albums/vienne-1900-alpha588
An interesting 2-CD compilation released yesterday, that explores the music and trends of early 20th century Vienna, and includes two rare transcriptions of Mahler songs.
Rather a mixed bag as far as UC-compatibity is concerned:
https://www.prestomusic.com/classical/products/8789365--vienne-1900 (https://www.prestomusic.com/classical/products/8789365--vienne-1900)