Back in the mid 70s Bryan Eno of Roxy Music fame, started the Obscure Music label where he produced records for av ante-guard musicians. One which caught my ear was an album by composer Gavin Bryares called, "Jesus' Blood Hasn't Failed Me Yet." Gavin recorded a street tramp singing a short improvised section of the hymn and he made a loop of the recording. As this loop recording played over the next twenty five minutes Gavin added strings and then fused in an entire orchestra.
Bryars made a new/shorter recording of the piece with Tom Waits (totally unnecessary) in 1990 which this video link below represents. The 26 minute original version is on You Tube as well.
Jesus' Blood on You Tube