too many things ...
wednesday electro clubbing for free in "Centrum",
friday hiphop in "C1", "musikpark" (yes with K, people must be stupid) every kind of mainstream,
rock in "engelsburg"
in Jena: go to the Casablancawhere they play nice music, many stilish pubs and bars, visit the INTERSHOP-Tower, enjoy the Zeiss-Planetarium, 2 Cinema-Complexes, stay in the Goethe-Galerie for some shopping, Jena is surrounded by one of the nicest landscapes of Germany and the University is worldfamous(17000 students), like many companies too, p.e. Carl Zeiss, Jenoptik, Intershop,Schott. Here are also many research institutes like Fraunhofer, many Bio-, Living- and Optronicaltech based Labs and Enterprises. You can also wander around in the nice landscape or do some daily trips to Weimar or even Leipzig, if you want.