There has to be enough definition to these four-note phrases for the audience to make sense of the music'

Cellist David Finckel leads the Zelda Quartet in a masterclass at The Juilliard School's Paul Hall.

The quartet play the Allegro non troppo from Johannes Brahms' Piano Quartet no.1 in G Minor, op.25.

Watch: Cellist David Finckel on the importance of using more bow

Read: David Finckel's 10 habits of successful musicians