Guitar,Piano,Vocal,Voice - Level 1 - Digital Download SKU: A0.1495772 By Billie Eilish. By Billie Eilish O'Connell and Finneas O'Connell. Arranged by HarperPianoSheets. Contemporary,Pop,Singer/Songwriter. Score. 2 pages. HarperPianoSheets #1072300. Published by HarperPianoSheets (A0.1495772). Beginner Piano sheet music arrangement by HarperPianoSheets 'Birds of a Feather' (Billie Eilish)Bridget Harper is a singer and pianist from Newcastle, NSW, Australia. She designs personalised wedding ceremony arrangements, and sheet music arrangements of all levels. Bridget graduated with a Bachelor of Music in 2019 and has since been tutoring students in piano and vocals. She has also been providing live music for weddings, functions and venues.