I truly understand what you're saying. The church I attend now very rarely sing hymns; but I've been to too many concerts and services, where a singer gets up and sings a hymn, he or she could be young or old; and the musician is clueless and then embarassed. Then another musician has to slide him, or her off. I've had to do that many times. A perfect example is, my group had to sing at anniversary of James Hall and Citadel. A group got up and sang, "Jesus, There is Something About That Name". A young man was on the organ fumbling with the song, even after they group told him the key. James Hall moved him over so fast it was so embarassing. I felt so bad for that young man. Now mind you, before all that happened he was on the organ playing these hot chords and changes.
I'm just saying we as musicians should never be caught out there like that.