How about LilyPond? It uses its own plaintext notation, but uses TeX for output. The engine itself uses a whole slew of measures to analyze the music and produce pretty sheet music, so it's automated to a much greater extent than MusixTex is.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…