Singing syllables are a type of vocalization used in singing and music education. The most common syllables are 'la', 'SOL', 'fa', 'mi', and 'RE'. The crossword solutions for the term 'singing syllables' include 'LAS' (3 letters), 'TRAS' (4 letters), 'LALA' (4 letters), 'LALAS' (5 letters), 'SOLFA' (5 letters), 'TRALA' (5 letters), 'LALALA' (6 letters), and 'TRALALA' (7 letters). These syllables are often used to teach vocal technique, pitch, and rhythm.