dd (6) going to friend's 7th birthday which involves High School Musical 3. Dd not seen HSM 1 or 2...

[LeCynic]

(I haven't seen it either, mercifully)

...will she be able to make sense of High School Musical 3 without having previously seen High School Musical 1 and 2?

Or should I try and hire the dvd's of the previous, no doubt rivetting, installments? (cringes at thought of having to watch alongside dd - since she will probably require explanation of plot)

Was I too rude about it?

.

I would imagine it would stand alone. On the basis of seeing number 1 (for research purposes as am music teacher and my pupils wanted to play the toons). I caught a bit of Number 2 on TV and although I recognised the characters the storyline seemed to be completely different.

I think just let her watch 90 minutes at her friends.

She will be fine.
The "storylines" don't follow on. The characters are just older.

Be prepared for her loving it and wanting to watch all three again and again and again.

....And I had been so pleased that so far we had managed to avoid it

There is nothing wrong with it, certainly not as dreadful as some people try to make out. Just a harmless fun musical which appeals to tweenie girls. Haven't seen 3 so can't comment on that.

christywhisty - not just tweenie girls, I took DSs 1,2 & 3 to see HSM 3 (we have 1 &2 on DVD) and they love them all. I haven't seen either of the others all the way through and it certainly didn't matter. IMO the messages are sensible without being twee, the songs are pretty likeable and you can safely let any child watch them without fear of anything inappropriate. I guess the only problem the OP might have is with all the associated merchandising which from what I've seen is aimed firmly at girls.