The outstanding reason for his preference for writing albums of short pieces (partly due, no doubt, to lack of time for more extended work) was that he loved to seize a passing impression or inspiration and to express it in music before it faded from his mind.  Nearly all his small pieces are musical photographs of the fancies of an impressionable and sensitive imagination.

The criticism sometimes heard that he was only good in small forms is, however, based on a fallacy due to an imperfect acquaintance with his work and is completely shattered by the indisputable greatness of his two concertos, of his four pianoforte sonatas and of the "Indian” Suite for orchestra.  The sonatas, although not all of equal value, comprise some of the finest pianoforte music in existence.  They are notable for their passion, breadth of style, massive momentum, dramatic power and eloquence of expression.  Admirers think them only equalled by such creations as Beethoven’s Sonata Appassionata.  It is curious that MacDowell’s sonatas are infrequently performed, for they bring the resources of the modern pianoforte into full and sonorous play, sweeping the whole of the keyboard with their stirring expressions.  It is possible that as they are not in general demand, the average virtuoso does not consider their technical difficulties worth conquering.  Nay, it is even doubtful whether the pianist’s mind could always rise to the heights of fervent poetry and imagination whither MacDowell was often carried and the memories of which are embodied in his finest music.

As a tone poet MacDowell has none of the sensuous emotionalism that wins popularity in the drawing room and at the musical recitals of popular pianists.  He is never sentimental and his strength and passion is always finely controlled, never feverish.  His music is singularly free from the emotionalisms of sex, the love-impulse with him is always noble and restrained.  In all his moods there is a human spirit and some definitely suggested content, the most notable purist exceptions being the two pianoforte concertos.  His tone colourings are never used densely or oppressively, but only serve to heighten the suggestiveness of the whole.  He loved the pianoforte as an instrument for personal melodic and harmonic expression, and understood the range of its tonal resources.  His biggest music for it is written with very broad and extended chords, strong in character, but always wonderfully clear and ringing, and eminently suited for pianoforte sonority.  His tone nuances range from a shadowy, mysterious pppp to a virile, massive ffff.

MacDowell’s best orchestral composition is his Second (Indian) Suite, Op. 48.  This is one of his most noble works, scored with masterly skill and vividly suggesting the great plains and forests, the wild and lonely retreats, the festivals, sorrows, rejoicings, and romances and also the stern, rude manliness of the North American Indians, whose pathetic annals form such a stirring page in American history.  MacDowell also wrote three symphonic poems for orchestra, another suite, and some symphonic sketches.