In fact, Maggie claims that it was The Beatles that taught her children how to write songs. In an interview with Variety, Billie and Finneas said that initially, the two of them wrote songs separately. “Ocean Eyes,” the song that started Billie’s rise to prominence, was written by Finneas. 

After that song’s success, the siblings started to write music together. Billie and Finneas said that between “75-80%” of their material is written together, often with one or both of them on an instrument.