From Beethoven to Verdi?

In preparing my listening skills for the opening of Giuseppe Verdi's Simon Boccanegra to launch the new San Francisco Opera season, I stumbled across a "family resemblance" that struck me as too good to be accidental. In the second scene of the first act, a crowd of angry protesters gathered in the street outside the Ducal palace bursts into the council chamber; and, for the life of me, I could swear they were singing Beethoven! Admittedly, Beethoven has been heavily on my mind lately; but, as Johannes Brahms once observed, it is very hard to listen to anything without thinking of Beethoven in one way or another. Nevertheless, this struck me as an outright case of appropriation, the source being the Presto movement of the Opus 130 B-flat major string quartet; and, while Verdi did not carry the initial motif in the same direction that Beethoven did, it is hard to dismiss this conformity as accidental.

This set me to checking some dates. Verdi wrote only one string quartet, which is actually the only piece of chamber music in the catalog of his works. He wrote it in 1873, which is interesting in light of the chronology of Simon Boccanegra. This opera was first performed in 1857, but it was revised in 1881. The Wikipedia entry describes the revision in terms of "text changes by Arrigo Boito" but says nothing about any revision of the music (or, for that matter, the extent of the text changes). Having never heard Verdi's string quartet, I have no idea whether or not Beethoven casts a shadow over its score; but it is hard to imagine Verdi having written it in total ignorance of at least some of the Beethoven quartets. Ultimately, I do not think this is a particularly big deal. (How does one say "Das bemerkt ja schon jeder Esel" in Italian?) Still, it may be a nice bit of insight about Verdi the listener that could inform our own listening practices.