Yes, there is a difference, at least worldwide on DVD Formats:
http://en.wikipedia.org/wiki/DVD_region_code
Essentially, the "Alizeé en concert DVD" was published in 2004 in the PAL Format which is, as I understand it, the primary European Format; also the German as well, if not mistaken. The difference is, not in the language but in the frames per second. The North American Format (NTSC) is Region 1 while PAL is considered Region 2. The difference is NTSC is, if not mistaken, 26 frames per second while the PAL is 29 1/2 frames per second. One can not play a Region 2 DVD on a primarily Region 1 (North American) player. The reading device wouldn't recognize it.
I think, again, if not mistaken, the first NTSC DVD version of "Alizée en concert" was in 2007 and was made in Mexico; this coming in the DVD+CD jewel case variety, if you have but a Region 1 DVD player. But upon recent investigation on ebay.com only one copy did I find and that was going for $ 99.99
Most North American stores that sell DVD players would be hard pressed to even know what is going on in Europe insofar as the music scene is concerned, yet alone about DVD players that cater to PAL. But there are cheap, Memorex for instance, DVD players that play multi-region (1 & 2) that go for about $ 20 to $ 30 range, but there are plenty of others as well. Check out the Internet for "Multi-Region DVD Players," and that would be a decent start.
I guess I can consider myself rather lucky in having three copies: the French original in the slipcase; the German International as well as the 2007 Mexican DVD+CD in the jewel case, which, as I recall, only cost me about
$ 20 to $ 25 at the time. This in case my PAL DVD player broke down. I think I'm on my third or fourth one now. The CD version came in a variety as well, I guess; one in a slipcase for that and one without; of which I've only seen one for sale and I just had to have that as well.