Nevertheless gold can be put to base uses. Scarcely had dilettantes discovered that the _da capo_ form could be used to give unity to some vocalist’s singing than they used it to give form to all sorts of formless things. We cannot at this distance imagine the vapidity of endless runs and roulades which passed in the seventeenth century for vocal music. Or at least we cannot until we see the actual fact on a cold printed page. And then, to do the seventeenth century justice, we cannot imagine the brilliancy of these same runs and roulades when brilliantly sung with the incomparable Italian vocal art of the time. Brilliancy of a kind! Let us call it brilliancy merely, and not plague it with the name of music. However that may be, we certainly cannot imagine the hold this institution of the aria had over the imaginations of the people of the time. To them it must have seemed the Muses on wings as compared with the Muses on foot. Aria became a science. More, it became a code of honor. Its nuances and conventions were tabulated as nicely as those of fencing or love making. A sin against the code was the unforgivable sin. There were, scientifically accredited, certain classes of arias with certain subdivisions thereunto appertaining. An opera must contain so many of each sort. Each major singer must have so many, no two alike and all equitably distributed. No aria must fall in the same class as that just preceding. There were many rules such as these, and more of the same sort which are well buried in dusty dictionaries. And if there were any to protest against such a condition they were promptly silenced by the statement that the arrangement was excellent for the singers.