Among the earliest recorded examples of African-American vocal-group music with elements of doo wop could be "My Prayer" by the Ink Spots, in 1939. It was certainly R&B with heavy elements of what would be known as Doo Wop. The Mills Bros. recorded "Till Then" in 1944 which certainly had all of the elements of Doo-wop, and might be considered as the first Doo wop song. These earliest known examples by the Mills Bros. and the Ink Spots, seem to indicate that the music was basically a form of harmonized blues. The ingredients are basically these: two or three part harmonies, along with elements of the blues; usually major and minor chords playing one after the other (or at least close); along with chorus and harmonic repetition. The subject of the music was almost always love and relationships.