(Σωσι), ἀπυκνος (φθορησι), among the ancient Greek writers on music, meant sounds not crowded together by small intervals. In particular, those three of the fixed or unalterable sounds of the ancient system which were called Proslambanomenos, Nete synemenos, and Nete hyperbolena. See Euclid's Harmonic Introduction; edit. Meibomius, pp. 6, 7.