Bill D., I didn't mean to be presumptuous. I attend several "song circles"--where folks take turns leading or presenting a song, and it can be a solo, duet, call and response, all-join-on-the-chorus, or group sing. I also attend one "jam/song circle" where it's explicitly expected that all songs to be sung by the group and, unless it's a very simple/familiar song, we are to use a book or provide lyric/chord sheets. I also participate in instrumental-oriented jams where folks [who are very good folk/bluegrass/Celtic/country musicians] refer to diminished chords and major 7ths as "jam busters" and prefer that you provide melody notation sheets when introducing an unfamiliar song, unless it's a pretty standard three or four chord pattern. [Several of these pickers can play fiddle, mandolin, guitar, bass, autoharp, and dulcimer and pick out melodies by ear if it's in the right genre, but I freaked 'em out by trying to do "Urge For Goin'" one time, because they didn't know the tune and Joni Mitchell uses chord changes that are unpredictable to a bluegrasss player. Individually, a lot of these folks can play jazz guitar or even classical, but they're not used to jamming unless it's bluegrass, country, or Celtic.]

Why should [some--many] songs be sung as a group?--Because you can get HARMONY, COUNTERPOINT, CALL-And-REPONSE, and a whole array of musical complexities that take an ordinary song and make it something incredible! A simple song like "Shortnin' Bread" can be fantastic when done by a group that can harmonize and embellish. [Barbershop and do-wop groups are great at this, not to mention a good Gospel choir.]

Besides there's something magical on a social-emotional level about blending many different voices into one song.

But I agree that some songs are best as solos.

Rich M., good point about the singing around the piano. Similarly, Alex's point about the symphony. FWIW, a lot of good pianists play with sheet music in front of them.

Crane Driver, I mentioned my choir above. Your post ties in with that. Choirs use sheet music [especially when singing Mozart, rather than Woody Guthrie] because the improvisation that a soloist can do will usually NOT work in a group of 40 voices.

FWIW, folks, I recently performed one of my own songs for the "open mic" at Singtime Frolics, and I blew an important line in spite of having the lyric/chord sheet on a music stand in front of me! I was so intent on singing the song TO the audience that I hardly glanced at the sheet and wasn't paying attention to it when I came to that line!

Genie