Crosby Stills Nash (& optional Young) are another obvious add to the list. Every song is three-part texture.
That is interesting.
Years ago, I has having trouble chasing down a song that I tended to think of as a vocal group song with rich harmony. Song turned out to be Jon Secada’s “Just Another Day” and apparently most people don’t think of or notice any harmony because it is styled as “background vocals” with Secada’s lead on the verses and predominant even in the choruses. But the harmonic texture is, for me, what makes the song.