I had once some conversation with Thalberg and Felix Mendelssohn, on the unmeaning names which musicians often give to their works, as "Concerto in F," "Concerto in B flat," "First Symphony," "Second Symphony," &c. Mendelssohn said, that though in almost every case the composer might have a leading idea, it would be often difficult, or even impossible, to give any title sufficiently comprehensive to convey the same idea or feeling to the mind of the hearer. But music, except to musicians, can only give ideas, or rather raise images, by association; it can give the pleasure which the just accordance of musical sounds must give to sensitive ears, but the associated ideas or images, if any, must be quite accidental. Haydn, we are told, when he sat down to compose, used first to invent a story in his own fancy--a regular succession of imaginary incidents and feelings--to which he framed or suited the successive movements (motivi) of his concerto. Would it not have been an advantage if Haydn could have given to his composition such a title as would have pitched the imagination of the listener at once upon the same key? Mendelssohn himself has done this in the pieces which he has entitled "Overture to Melusina," "Overture to the Hebrides," "Meeres Stille und Glückliche Fahrt," "The Brook," and others,--which is better surely than Sonata No. 1, Sonata No. 2. Take the Melusina, for example; is there not in the sentiment of the music all the sentiment of the beautiful old fairy tale?--first, in the flowing, intermingling harmony, we have the soft elemental delicacy of the water nymph; then, the gushing of fountains, the undulating waves; then the martial prowess of the knightly lover, and the splendour of chivalry prevailing over the softer and more ethereal nature; and then, at last, the dissolution of the charm; the ebbing, fainting, and failing away into silence of the beautiful water spirit. You will say it might answer just as well for Ondine; but this signifies little, provided we have our fancy pitched to certain poetical associations pre-existing in the composer's mind. Thus not only poems, but pictures and statues, might be set to music. I suggested to Thalberg as a subject the Aurora of Guido. It should begin with a slow, subdued, and solemn movement, to express the slumbrous softness of that dewy hour which precedes the coming of the day, and which in the picture broods over the distant landscape, still wrapt in darkness and sleep; then the stealing upwards of the gradual dawn; the brightening, the quickening of all life; the awakening of the birds, the burst of the sun-light, the rushing of the steeds of Hyperion through the sky, the aerial dance of the Hours, and the whole concluding with a magnificent choral song of triumph and rejoicing sent up from universal nature.