Brilliant! Nothing better than the lovely twinkly sound of a group of mandolin players. I've never seen so many different sizes of mandolin. The guy at the back with the "double base style mandy" looks like he has a cartoon instrument. I bet their arms hurt at the end of a performance.
Links off that page are a black hole that could lead to you spending hours downloading Jewish music in umpteen formats and trying to work Flash players in Hebrew. "Sholom Aleichem" is in this large collection edited by Goldfarb himself:
That version will work nicely on the G or C clarinet.
Incidentally the tune at the end of the Ger ensemble video is one I know of as a Hungarian tune played by the Csango (Hungarian Catholic) minority in Moldavia and eastern Transylvania - I learned to play it from a Hungarian whistle player and have done the dance that goes with it (the tune is repeated over and over again for a trance-like effect resembling techno). I suspect it may be Romanian originally.
[Later:] I found it on one of my CDs. It's called "Perenyica", but I can't find a video of the Csango version on the web. There is a Romanian version from a wedding in France under the alternative name "Pelenita", the tune is recognizable but not performed very well:
The idea is that one couple is in the centre of the circle - they birl around a bit with their hanky while the circle oscillates round them, then they separate, one going back into the circle and the other offering the hanky to a new partner. You don't necessarily have everybody from the circle doing a turn in the middle but it can go on for a very long time.