catarina: Where do you come from btw?
And which genres of music do you prefer?
Because if celtic - Zuzana advised you a very good ones, I would add Jan Hrubý - he composes his stuff with some "celtic" influences. Some things by him are truly magnificent.
And there is a lot of good "celtic" stuff, I think it is kind of modern to play it. There is a problem, that some people who listen to czech irish music add additional czech influences, so it is rather czech traditional with irish influences. And they call it irish music.
But anyway, we have a lot of good ones
(I would suggest MARW - Welsh music - now it is pretty famous...grrr...I could play in it but I refused as it wasn´t good enough to me

)
Momma, I wanna be famous:-) In fact I don´t.
And I would strongly suggest Tři sestry. They are influenced by Pogues, they even covered Sunnyside of Street (in czech it sounded pretty funny)
and their leader states that the Pogues are the best band at all.
And btw it is probably the most famous czech band now.
Which parts of Czech Rep. are you expecting to visit?
I would suggest you Prague, then Prague and Prague.
Sometimes I just think it is too good to be true...