What was the Brahms (?) piece Beverly kept playing?

It’s a piano arrangement of the theme from the third movement, Allegro giocoso, ma non troppo vivace – Poco più presto (D major), of Brahms’ Violin Concerto in D major, originally written for solo violin and orchestra. Brahms reworked the theme for his ‘Piano Concerto No. 3 in D Major after Violin Concerto’, as well as arranging the Violin Concerto for solo violin and piano. There is also a solo piano arrangement by Paul Klengel. Here it is in its original form: https://www.youtube.com/watch?v=Gk_e0C_Pnwo