U2 played some very small venues when they first came to mainland Europe, around 1980. Their drummer was not even 18 at the time, which was part of the reason for using aliases.
I clearly remember watching them do I Will Follow on a Belgian TV show G?n?ration 80, against a backdrop of the album cover of Boy - not sure if they lipsync'ed or played live. I could have been at their gig in my then home town of Tilburg, but you know how things go - anyway, I got the Boy album before most people had ever even heard of U2. That same tour they played in Etten-Leur, which is a small town where nothing happens - well, most of the time.