Alistair,
Thanks for the link. That was great.
The thesis speaks to the importance of Partido Alto. It doesn't, to my reading, justify the notion that Partido Alto is the trunk of the tree.
It is, of course, an important rhythm to know.
Some of his examples strike me as more general samba than specific to PA. The thing that always feels different about PA is that sequence of 4 downbeat eighth notes in a row (in 2/4). Some of his examples don't have that.
By the way, he uses Viva Brasil as an example. My teacher, Marcos Silva, was the keyboardist and arranger for that group. Their CD, Festa, (not the one the example is taken from) is one of my all time favorite recordings.
In case anybody wants a clear recording and chart, check out Airto's "Partido Alto". The Latin Real Book has the chart.
Rick
Rick