Opus 51 by Joseph Haydn [1732–1809] was composed as an orchestral piece and was first performed for a Good Friday service in 1783. It was subsequently arranged for string quartet, as an Oratorio, and was also published as a piano arrangement. It exists under many names; I have seen examples ranging from The Seven Words to The Seven Last Words of Our Saviour on the Cross.
Haydn was a devout Catholic and the string quartet arrangement is a quiet, meditative piece; its mood truly reflecting the sombre nature of the title. The most unusual aspect of the work is that all movements, with the exception of the last, are taken at very slow tempos. The score is littered with tempo markings of adagio, lento, largo and grave. This gives the work a prayer-like quality and allows Haydn the opportunity to craft some transcendent melodies. There is some wonderful music here. The last movement is a satisfying forceful and almost symphonic finale.
Ultimately this is a spiritual and thought provoking quartet. I have not heard anything else like it.
I have fine performances by the Amadeus Quartet on Deutsche Grammophon and the Rosamunde Quartet on ECM. I can also recommend the version by the Kodaly Quartet on Naxos. There are several versions of the quartet on Spotify and YouTube, while earsense has ten versions of the work, including the superb Amadeus Quartet recording.
Listenability: A wonderfully spiritual quartet from the Classical master.