"Watermark" firmly established Enya's sound of multi-layered vocals, keyboard-oriented songs, and influences of Celtic music. Enya felt the need to have layers of vocals to add a "human element" to her music as solely using keyboards and digital sampling sounded, to her, "a bit linear and straight". The idea of the multi-vocals originated when Enya was a member of Clannad, her family's Celtic band, in the early 1980s. With Nicky as their manager, influenced by The Beach Boys and the "wall of sound" technique made famous by producer Phil Spector, the two often discussed the idea of layering Enya's voice to make it its own instrument. After experimenting with the concept on "Enya" the vocals became more established on "Watermark", with as many as over 200 vocal tracks were painstakingly recorded for certain sections. In one instance, around 90 tracks had been put down during a period of several days but the two felt they did not sound right, so they erased them and started over. This was the case particularly during the recording of "Miss Clare Remembers", a piano instrumental, when they experimented with the idea of adding vocals but decided against keeping them.