Tchaikovsky did not devote his most serious compositional efforts to these pieces; they were composed to order, and they were a way of supplementing his income. He saw the writing of music to a commission as just as valid as writing music from his own inner inspiration; however, for the former he needed a definite plot or text, a time limit, and the promise of payment at the end. Most of the pieces were in simple ABA form, but each contains a minor melodic masterpiece.