The term 'at a moderately slow tempo' can be expressed in musical terms with the words ANDANTE, ADAGIO, allegretto, and andantes. ANDANTE is a 7-letter word meaning 'at a walking pace, ' ADAGIO is a 6-letter word meaning 'slowly and gracefully, ' allegretto is a 10-letter word meaning 'moderately fast, ' and andantes is an 8-letter word meaning 'somewhat slow.' These words are used to describe the speed of a piece of music, with ANDANTE being the slowest and allegretto being the fastest.