if u wana play rhythm loops along with the other band members and
the drummer live onstage without the click track it is not possible
u can only play with live as a dj who is only playing alone
but to play with the orchestra or band with fluctuating tempo
u cant join in its very risky
for example
the situation is diff here
10 people are playing rhythms
and there r various pickups in between and the groove keeps fluctuating a bit as there r so many players invovled
and after a pick up there is tend of fluctuation to happen in the tempo so than to start with exact tempo according to the band
is not possible
http://www.youtube.com/watch?v=ZrS1Bgf9l2U
here is the link where u can see how there r changes n the style of music happening
so to play with this group of members u need to follow them not they need to folllow as its better one following 10
rather 10 following 1 
there need to be something like tap tempo the way u play or trigger ur samples on fly
i.e if u hit the key sample slow the loop will slow down
and if u hit the loop fast it will speed up according to ur finger hit ...on fly
and u will manage the sync with the band on fly
hope u guys r getting what i m trying to explain 
if any body has done this plzzzzzz put some light on this
the tap function is not good idea for for live if u playing along with 5 member of band
u need actual tap tempo which is on fly and works as proper in sync with the band.
current tap tempo is just good for coming in n going out,.... what dj's do
but when a song is happening for 3 min and the loop has to be played
till than with the band u need to be accurate with the fluctuating tempo
the tempo should keep changing the way u hear the rhy and play.
Ableton guys should do something for such kind of scenarios ?????????????
any video or ideas to help me out will be appreciated
Oh yeah!
http://www.b-keeper.org/index.html