This is probably the most popular bossa nova that was NOT written by Tom Jobim. Written by Marcos Valle, "Summer Samba" is a gentle song with a lovely melody.
The song form is not very complicated. It is a 32-bar song in ABAB form. The A sections are identical. The B sections are similar. On the out-chorus, we tag the last 4 bars several times while fading.
Trivia: "bossa nova" literally translates to "new trend." The style emerged in the mid-20th century, after the WWII swing era as a fusion of the samba and jazz. The samba is usually a faster 2-beat, and considerably more frantic. Most jazz music at the time was counted in 4. The bossa became the dominant jazz style when playing straight eighths, as an alternative to the the swing, shuffle and boogie songs that dominated during the WWII and early post-war years. The bossa is almost always counted in 4 beats and generally features a clave pattern that spans two measures -- either a 2-3 or a 3-2 pattern (i.e. 5 clave beats every two measures.)
This arrangement uses a very strong 2-3 clave. And you hear the guitar playing that same pattern much of the time.