In March and April 1970, Lupu made his first recording for Decca Records of Brahms' Rhapsody in B minor (Op. 79 No. 1) and Three Intermezzi (Op. 117), as well as Schubert's Piano Sonata in A minor (D. 784). He has remained an exclusive Decca artist, and continued to record for the label for the following 23 years. In August 1970, the 24-year-old pianist made his debut at The Proms, performing Brahms' Piano Concerto No. 1 (Op. 15) with the BBC Symphony Orchestra conducted by Edo de Waart at the Royal Albert Hall. In November 1970, he made his first concerto recording for Decca, of the Beethoven Piano Concerto No. 3 with the London Symphony Orchestra conducted by Lawrence Foster; he also recorded Beethoven's 32 Variations in C minor (WoO 80).