Musea
There are many musea to visit in Ghent. On the picture you see the beautiful building where the Alijn House (museum of folklore) is housed in.
Overview of musea

Ghent Opera House
There are several halls (the foyer, the ballroom and the concert hall) and they are all just as stately, elegant and beautiful. One Saturday a month there is a guided visited. Look on the website for the program of opera, concerts etc.
Schouwburgstraat 3, tel.: +32/(0)9/ 225 24 25
http://www.vlaamseopera.be/

Gentse feesten
They are well known: The Ghent Festivities. 10 Days (mostly in June or July) of free feasts, music, theatre etc. on several squares in the historic centre of Ghent.
More information about the Ghent Festivities