Besides other means of recreation, Carleton was happy in having been from childhood a lover of music. In earlier life he sang in the church choir, under the training of masters of increasing grades of skill, in his native village, at Malden, and in Boston. He early learned to play upon keyed instruments, the melodion, the piano, and the organ, the latter being his favorite. From this great encyclopaedia of tones, he loved to bring out grand harmonies. He used this instrument of many potencies, for enjoyment, as a means of culture, for the soothing of his spirits, and the resting of his brain. When wearied with the monotony of work with his pen, he would leave his study, as I remember, when living in Boston, and, having a private key to Shawmut Church, and dependent on no assistance except that of the water-motor, he would, for a half hour or more, and sometimes for hours, delight and refresh himself with this organ,--grandest of all but one, in Boston, the city of good organs and organ-makers. Many times throughout the war, in churches deserted or occupied, alone or in the public service, in the soldier's camp-church or meeting in the open air, wherever there was an instrument with keys, Carleton was a valued participant and aid in worship. Religious music was his favorite, but he delighted in all sweet melodies. He loved the Boston Symphony concerts and the grand opera. Among his best pieces of writing were the accounts of Wagner's Parsifal at Bayreuth, and the great Peace Jubilee after our civil war. At most of the great musical events in Boston, he was present. Shawmut Church had for many years one of the very best quartette choirs in the city, supported at the instrument by such organists as Dudley Buck, George Harris, Samuel Carr, H. E. Parkhurst, and Henry M. Dunham. In Carleton, both voice and instrument found so appreciative a hearer, and one who so often personally commended or appraised their renderings of a great composer's thought, or a heart-touching song, that "as well the singers as the players on instruments" were always glad to know how he received their art and work. In Europe, this lover of sweet sound enjoyed hearing the greatest vocalists, and those mightiest of the masses of harmony known on earth, and possible only in European capitals. Before going to some noble feast for ear and soul, as, for example, Wagner's rendition of his operas at Bayreuth, Carleton would study carefully the literary history, the ideas sought to be expressed in sound, and the score of the composer. In his grand description and interpretation of Parsifal, he likened it among operas to the Jungfrau amid the Bernese Alps. "In its sweep of vision, beauty, greatness, whiteness, glory, and grandeur, it stands alone ... to show the greatness, the ideal of Wagner, including the conflict of all time,--the upbuilding of individual character,--and reaching on to eternity."