1) Yes they are. Nowadays, more and more open air gigs take place during holidays, so a lot of young people go for them. The most popular one is Heineken Open’er Festival, which is said to be one of the best festivals in whole Eastern and Middle Europe.
2) Mostly it is pop and electronic music (as on Coke Live in Cracow) and rock on Heineken Open’er in Gdynia.
3) Few years ago there was some kind of ‘boom’ for folk music played by Brathanki and Golec uOrkiestra. Everybody was listening to them. But now this bands disappeared and I don’t know any folk music band, which plays recently.
4) Well, I think violin is quite popular and I think accordion, maybe mouth-organ. And, excluding violin, none of my friends learn how to play this instruments, I think young people learn how to play them, only if it is a family tradition.
5) It doesn’t, because it is not very popular. Folk music is not played in radio, there are no folk music concerts, so its influence to pop is rather weak.