[...] In reading through the "Cherubini" the following superficial ideas occurred to me, which I am not much inclined to recommend for further working out. Thus:
(1) Tragedy of Rossini, who could invent new melodies, but could carry through no sustained and orderly work.
(2) Tragedy of Schumann, who never achieved any melodies at all.
(3) Tragedy of Brahms, who—despite great fullness—is always tedious.
The tragedy of Mendelssohn, who could never find a really German operatic libretto, has already been treated by E. Devrient.—
There are also various other tragedies. [...]
Source: Letters of Richard Wagner, Vol. 2, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 732