Perfect 
the three baroque concertos (or concerti, if you really are an italian) from tuesday evening's concert all stem from the body of music which treads the line between chamber music & orchestral music; indeed, prior to the rise of the so-called 'authentic performance' movement would often have been performed as orchestral works.
the jansen ensemble, led by violinist janine jansen, whilst not quite performing in the totally authentic camp were certainly well in the spirit of it - a single player per part, & the musicians all (where feasible) standing to play rather than taking it easy on the award-winning symphony hall chairs.
opinion is still divided as to whether there is a right or wrong way to perform baroque music, but for myself i certainly prefer to hear it cut back to the minimum, in order that the baroque twiddly bits (which are, after all, the point of the genre !) can be heard, & you still get a 'big' sound. performing this way also assists in holding to the original baroque idea of a concerto which was more of a piece having a featured instrument(s) but with the rest of the ensemble being just as important, rather than the later concept of a definite soloist with mere accompaniment from the orchestra.
in the first half of the concert we heard two bach concertos - the concerto in d minor (bwv 1052)& the concerto no. 2 in e major (bwv 1042).
to my mind, bach is, well, bach really; music students mimic bach as technical harmony exercises, & one of his most famous works, the collection of keyboard studies known as thewell-tempered clavier was written less as music to be listened to by an audience & more as a showcase for the great new tuning system he was wishing to promote.
most of his concertos were recycled from one instrument to the other, often in a hurry to meet a tight deadline, thus establishing bach in his time as being more of a composer of library choons than the precious bohemian artist we usually associate composers with.
so for the most part it's difficult for me to get worked up about his music - generally, people will either play it well or they won't, without as much scope for getting serious emotion in there as with later work.
the jansens were definitely in the well department, though occasionally at times i did detect some of the ensemble playing go a little awry - it was then that i realised they were visibly playing less as a group & more as individuals playing together, without the visible interaction & playing (in the sense of a game) which separates the good from the great. this though could be excused with the knowledge that their usual first violinist was taken ill before the concert, replaced almost literally at the last minute by melinda madozzi.
the second half of the concert was the main event - vivaldi's four seasons. commonly presented as a single work, it is actually four separate pieces which are themselves part of a body of 12 concertos collectively titled the trial between harmony & invention, catalogued as vivaldi's opus 8.
this thus lead to the embarrassing moment at the end of the first concerto, spring, which a few members of the audience thought was the correct time to applaud - clearly though whether they were right or not, they gave in to the peer pressure of the majority keeping their hands to themselves for the rest of the evening until the very end. classical music applause etiquette does amuse me, especially given that outside white british culture audiences will generally clap whenever they feel the performance deserves it rather restricting themselves to the 'correct' time to do so!
vivaldi has always been a baroque favourite of mine, & it was clear he's a favourite of the jansen's too - although some of the ensemble difficulties of the first half were still present, & some of the endings it has to be said were a bit sloppy, the interaction between them was much more evident, as was the joy of performing vivaldi's music.
overall, janine jansen & her ensemble, whilst still having work to do before the artist-marketing-epithet "leading international performers" will genuinely apply, gave a concert which, though not life-changing, was definitely respectable & creditable. on leaving the hall i heard somebody behind me, in his early-20s so perhaps a music student, say to his colleague "technically: excellent, musically: very good". i think that's a fair summary.