Above all, his musical opportunities were good and varied, and he took the fullest advantage of them. Music in Edinburgh had, for many years, maintained a high standard. The orchestral concerts were second only to those conducted by Hallé and Richter; the latter brought his own band occasionally, and every solo player of eminence came there from time to time. He found many congenial friends, and was a frequent guest at the houses of Mrs. Sellar, the widow of the Professor of Humanity at Edinburgh, and Dr. Berry Hart, the famous surgeon, where musical amateurs met constantly; and he was a member of the "Rhyme and Reason Club," where literary and artistic questions were discussed. His most noteworthy contribution to the Club was a paper on the "Relation of Music to the Words in Songs," which he afterwards read at the Manchester College of Music, and which well merits a summary here (and some extracts). It shows how his mind was steadily working in the direction of musical criticism. Its origin was a statement made in a paper on Tennyson's songs, that poetry, if it be true poetry, is self-sufficient, and the addition of music to it, however fine the music may be in itself, is an intrusion and a disturbance for the true lover of poetry. The first part of his paper is concerned with an examination into the nature of music and its place among the arts. He goes on to deplore the divorce between music and the songs of modern English poets, none of which are capable of being sung, and traces this divergence back to the days when Puritanism banished music from church and village green. Burns, he adds, wrote genuine songs; but he is the only song-writer since the days of Elizabeth, and worthy of being ranked with Heine. He concludes by claiming for music "that it is not an inferior art, a mere hand-maid to poetry, but a direct revelation of the principle of beauty and on a footing of honourable equality with poetry. The songs of all the really great lyrical poets are obviously and radiantly singable, and meant to be sung, and in their authors' lifetime they were sung. So far then from the finest lyrical poetry being impaired by association with music, it is only the maimed poetry of decadence that does not admit of such association, one unfailing mark of a lyric of the highest order being that it rises to the true singing quality." In the following passage Johnstone sets forth the ideal at which the composer of songs should aim:-- "The great German song composers, such as Schubert, Schumann, Franz and Brahms, working in profound sympathy with the 'Volkslied,' have arrived at a conception of the song infinitely richer, more refined, and more genial than is to be found elsewhere. With Franz and Schumann we find that, in the best cases, the music positively furnishes a sort of literary criticism on the text, with such exquisite exactness does the composer appreciate the text and supply the appropriate musical counterpart.