A tune connection I noticed just yesterday has captured my attention because there's so little similarity of actual pitches, to the point that these really aren't close to being the same tune - but, at a slightly higher structural level, they are closely related. It's a gestalt thing. And, as is always most interesting, it's not a connection that came to me because I looked for it (I'm too lazy to do research), but rather that dawned on me slowly and, at first, subconsciously. This theme from the finale of Mozart's "Dissonance" Quartet, ambled by...
...and as I listened, I kept thinking that those staccato 8th notes in the 2nd half of the phrase reminded me of...something. Eventually, the theme from the finale of Brahms' Clarinet Sonata No.1 (the piano part of which I've played many times) raised its hand in some corner of my mind (here transposed from F to C to make comparisons easier).
Of course, neither phrase is particularly unusual in terms of phrase construction - each begins with two upbeats, then longer notes and a slow-ish harmonic rhythm followed by harmonic acceleration towards a half cadence. It's definitely those pairs of staccato 8ths notes that connect the two tunes, even though Mozart goes up where Brahms goes down. The openings of the two phrases don't share so much in common other than a general twisty-ness, but each leads into the staccato 8ths with the same melodic pattern (see circled notes below): three 8ths descending stepwise, then a drop of a 3rd to introduce the "paired staccato motif" which jumps up a 4th heading into the next bar. It's striking to me how similar the tunes sound even as they then head in opposite directions; and, because the circled sequences below begin a 4th apart, the parting of ways leads each to arrive on D at the same time.
So, that's really about it. The two good-natured tunes are clearly quite different, but what makes each memorable (to me, at least) are those bouncy 8th notes. I don't know if Brahms was somehow inspired by Mozart, but I love hearing this kind of kinship. As I've said many times before, there's an obvious analogy to puns and other types of linguistic references, and just as I can't seem to avoid looking for wordplay possibilities when words are in play, my listening ear loves to play pattern-matching games. Surely, on some level, listening to music is basically about pattern-matching, although no one wants to think about that too much.
By the way, since we're on the subject, my favorite moment in this Mozart movement comes a bit later in an exquisitely Schubertian chromatic mediant modulation. The music has been cruising along in the Dominant key, G Major, and the first violinist seems to get stuck/lost in a maze of 16th notes; abandoned by the other instruments, the violin tentatively hangs onto a D (Dominant of G) and then suddenly the violin sneaks up a half-step as we drop by a third into the distant key of E-flat Major. The lovely scoring for violins in octaves somehow complements this shape-shifting perfectly as they music gradually finds its way back, but as ever, it's the searching that we (I) remember.
Passages like this one fascinate me because when I'm listening to a piece like this, I've found that much of my pleasure comes from anticipating and then enjoying these very small moments; much of the rest of such a movement will often strike me (dodging lightning bolt) as rather formulaic. It may not be fair to Mozart to say this (quantifying pleasure is risky business), but I if I'm honest, it's as if 50% of my interest in this piece takes place within about 5% of its discourse. But that's a difficult topic for another day... (I have written about it before, with passing reference to the famously "dissonant" introduction to this same quartet.)