Enya is the sole composer of the music on "The Memory of Trees" and co-arranged them with Nicky. It is her first album not to feature guest musicians. In addition to the vocals, piano and an array of keyboards and synthesisers that defined her sound, Enya plays the violin, cello, and percussion instruments. Her method of songwriting had deviated little since the start of her career, which started by entering the studio and forgetting about past successes. Ideas are then put on tape as either a vocal or a piano melody. "Usually what happens is the first note, the second note, and it takes me on a journey and I just go along with it." When a collection of ideas have been recorded Enya presents them to Nicky, starting discussions on how to develop them further into songs. Roma will then work on a lyric if she feels the song would suit one.