Alan Parsons miked the Atom Heart Mother choir with a Blumlein pair in Abbey Road Studio One

The biggest headache with the 60-piece ensemble on “Atom Heart Mother” wasn’t the size of the room — it was keeping the orchestra from bleeding into the band’s amps while keeping the choir clear. Studio One is huge, but Pink Floyd and the John Alldis Choir were all playing at the same time, live, with no isolation. Engineer Alan Parsons had to make the classical side sound both present and natural without turning the session