Psalm 51 is such a towering and famous peak in the landscape of the history of the psalms. A quick look at the choral online directory CPDL gives you the picture — I haven’t counted how many entries appear on that Psalm 51 page. One hundred?
Second on the list is that famous Miserere mei Deus by Gregorio Allegri. But I’ve told that story about Mozart and the Sistine before, most recently when it came up earlier on 21 March this year.
Then there are the equally towering works by Orlando de Lasso inspired by this fourth or middle of the seven Penitential Psalms. That is also described elsewhere.
Closer to home in the search for an easier solution, there are no less than fifteen settings in Psalms for All Seasons. The first of these 51A is ‘The sacrifice you accept, O God’, which is as good a place to start as any.
There are even two songs in Together in Song, numbers 31 (Hopson) and 32 (Willcock).