The "side-ways rhythm" perception is for the fact of the research that
Julia Brown developed about the interpretation of the Baroque Music and
Bach in particular.  This research is based in the notion that what is
written in the score is a basic reference for the execution.  Thus, for
example, the interpreter can alter the ornamentation, the rhythmic detail,
the speed and same to increase some expressivity (characteristics not
always clear in the score of those times).

I compare with the Pop Music: here the interpreters - singers or
instrumentists - have an original text (melody/lyric line, chords
progression, regional rhythmic patterns and swing) and they make new
arrangements for each show.

We should also remind that the Baroque Music was interpreted in the
"romantic way" or in a "mechanical way".  In the last 20/30 years a
movement began (of the which Julia Brown is part) of to go to the Baroque
original sources and to rethink the interpretation of these pieces in the
encounter of more historical authenticity - or, at least, to try this
possibility.

The current researchers believe that the Baroque composers had this
freedom in mind.  It is necessary to remind that Bach, Haendel, Corelli,
Vivaldi, Frescobaldi, Couperin, among others, was great masters of the
improvisation.

There is a good book to begin understand: "Guide to ornamentation in
Baroque Music" - H.M.  Linde

PS: Here in Brazil we used the term "metrica relaxada" ("relaxed metrical"
or "loose metrical") for these subtle and expressive alterations of the
rhythm.

Edson Tadeu Ortolan
[log in to unmask]