Lord Neaves adverted to the peculiarity which had been observed in many Scotch airs, that they are composed on a pentatonic scale, and do not make use of the fourth or seventh of the gamut. It has been said that these airs can be played on the black notes of the pianoforte, which means that they can be played on the key of F# major, of which the fourth and seventh are represented by white notes, but are not needed. He also observed that this class of airs could be played on the white notes of the piano, both in the key of F and in that of G.