I enjoyed the demo and I appreciate how the hymn is played: with a few bars of intro first, before the singing proper would begin. This is a very helpful aid to congregational singing, to cue everyone in on the key, tempo, and melody being used. Traditionally, it has not been uncommon for congregations to sing in four-part harmony, perhaps aided by hymnals with real music notation, or sometimes, people know how to improvise a harmony in their own range.
When many small and/or rural congregations are struggling financially just to keep their lights on while also paying for a pastor's salary and upkeep on their parsonage, the decision to allow a RPi MIDI system for a few hundred dollars one-time cost vs a few grand annually for an organist becomes an easier decision.
But for churches who prohibit recorded music, their recourse is to mothball the organ, and have somebody pull out an acoustic guitar, and there you go.
