During the days of RAFLOST there will be other interesting things in Reykjavik as well:
On tuesday the 18th there is a concert of electronic music by students of Kopavogur Computer Music Center. The concert takes place in Salurinn, Kopavogi, about 20 minute bus trip just outside of Reykjavik. [ Sorry, this concert was moved to the previous week, and is not a part of the festival. Two pieces from that concert were featured on the Saturday 15.5. happening at Útgerðin. ]
The Iceland Art Academy music student concerts will be happening during 17.4 – 30.5 2010. An overview of the concerts can be found here. Its in icelandic but you see that people are marked by their instrument names, except “tónsmíðar” means composition and “nýmiðlar” means new-media.
Also, check the Reykjavik Grapevine for various events in the city.