To be deductible, a business expense must be both ordinary and necessary. An ordinary expense is one that is common and accepted in your trade or business. A necessary expense is one that is helpful and appropriate for your trade or business. An expense does not have to be indispensable to be considered necessary. It is important to separate business expenses from the following expenses:
A duple meter metronome that is useful for 2/4, 2/8, 2/2 (cut time), and 6/8 when it has two beats per measure.
Duple Meter Metronome This metronome produces a high click on the downbeat, followed by a low click on beat two. It is useful for practicing music in 2/4, 2/8, 2/2 (cut time), or 6/8 when it is a compound meter and the dotted quarter note equals one beat.