The other night, picking up after dinner, we had "Classic Arts Showcase" playing on the TV, and a video came up with Aaron Copland's "Laurie's Song," from his opera The Tender Land (premiered 1954). There's a phrase with a similarity to "Estrada do sol" that's hard to miss, right at the beginning, in the instrumental introduction.
I think it's quite possible that Jobim consciously borrowed that melodic phrase from Copland; there are a number other instances of his borrowing musical ideas (from both classical and American popular sources) and using them in his own way.
Besides the melodic phrase, the pieces have a bit of harmonic similarity. In "Laurie's Song," the harmony seems (to me) to start with repeated Bm to C chords, creating a temporary B phrygian feel, eventually resolving to G major. "Estrada do sol" begins with a Dm7 G7 vamp, giving a temporary D dorian feel, resolving after 8 bars to C major.
This device - beginning in minor (in "Estrada do sol," D dorian), dwelling on it long enough to establish the minor key as tonic, then resolving it to the "relative major" (here, C) - shows up in some well-known tunes that predate both the Jobim and the Copland. Bronislaw Kaper's "Invitation" (1950) does this, as does Ary Barroso's "Na baixa do sapateiro" (1938).
Here's a Toquinho version of "Na baixa" that starts with the vamp in question:
You can find the music to "Estrada do sol" on jobim.org (click here), along with a wealth of other Jobim resources.
