Do you find the Graduals and Alleluias in the Liber Usualis daunting?
In 1926, the Solesmes monastery produced this wonderful book of reduced Graduals, Tracts, and Alleluias. They are for singers who find the full versions daunting, but don’t want to resort to Psalm tones. Their level of difficulty is more along the lines of the Introit or Communio, so they are approachable. This makes this book invaluable for scholas without decades of experience. It includes chants for the entire liturgical year according to the traditional calendar.
The original is in French, as are the titles, but the index is complete so you can easily find the chant you need to sing. The typeface is flawless.