Bass and Harp are two musical instruments that have been around for centuries. The Bass is a stringed instrument that produces a low-pitched sound, while the Harp is a plucked instrument that produces a higher-pitched sound. Together, they create a unique and beautiful sound. The crossword solution ALES is an acronym for the two instruments, which stands for 'Acoustic Low End Strings' and 'Harmonic Arpeggio Plucked Strings'.