the first and the second last are quite good. their stage setup with everyone sitting behind mike stands and music stands would be a real challenge to say the least.
#1 is the best here i think good composition and exposure
#2 the composition and shot is generally blah. and focus is missed i think
#3 is focused on the stands (manual focus would have helped)
#4 is actually not bad nice and moody but there is no specific subject
#5,6,7 are all reasonable, the performers themselves aren't doing anything exciting but they are well captured
Shooting live music is always a challenge (light changes constantly and is rarely very strong, then there is capturing the moment- here it helps to know the performers from previous shows or just be familiar with their style so you can track for it. I've shot a lot of shows over the years and some musicians are tough to capture no matter what as well (rock shows are far easier IMO because they can be more animated in general than classical. the 43 definitely is a good lens to have in your arsenal for this. a DA* 50-135 or a 70-200 2.8 is also an excellent tool. I do shoot a lot of shows with Manual focus lenses but it means a smaller keeper rate (and generally less shots overall)
This is one of those things that the more you do it the better you get. Fortunately it costs nothing to shoot more frames in digital (I've shot shows in the 70's on bulk loaded b/w film and would have to limit myself to 1 or 2 rolls of 36 being too poor to shoot more - sometimes i would only walk away with a couple of shots i was happy with. Digital made me much better at it when i returned to shooting music in 2006 and could review as i went.
the hardest thingh is when you are on a press pass and have only 2-3 songs at the beginning of a show in the pit to get the shot. the band is rarely warmed up and putting on the best part of the show. I had this discussion with Iggy pop once when he complained that concert photography isn't what it was in the 70's, I countered saying in the 70's i could shoot a whole show with may camera unhindered by security goons and could then wait for him to really get going mid set