McCartney's father was a trumpet player and pianist, who had led Jim Mac's Jazz Band in the 1920s. He kept an upright piano in the front room, encouraged his sons to be musical and advised Paul to take piano lessons, but Paul preferred to learn by ear. [nb 1] At age 11, he encouraged Paul to audition for the Liverpool Cathedral choir but he wasn't accepted. Paul then joined the choir at St Barnabas' Church, Mossley Hill. He gave Paul a nickel-plated trumpet for his fourteenth birthday, but when rock and roll became popular on Radio Luxembourg, McCartney traded it for a £15 Framus Zenith (model 17) acoustic guitar, since he wanted to be able to sing while playing. He found it difficult to play guitar right-handed, but after noticing a poster advertising a Slim Whitman concert and realising that Whitman played left-handed, he reversed the order of the strings. McCartney wrote his first song, "I Lost My Little Girl", on the Zenith, and composed another early tune that would become "When I'm Sixty-Four" on the piano. American rhythm and blues influenced him, and Little Richard was his schoolboy idol; "Long Tall Sally" was the first song McCartney performed in public, at a Butlin's Filey holiday camp talent competition.