Barcelona for DH and friends

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DH and four university friends are going to Barcelona for 5 days for 50th birthday/reunion. Can you recommendation a nice restaurant for b'day dinner, day hikes or good running routes, and bars/restaurants with music? They are a tame lot and mostly looking forward to reuniting but also don't want to end up in tourist traps.

Barcelona is a proper city so a lot will depend on where they are staying. There are way more tourists than residents so anywhere becomes a tourist trap once a few people know about it.
Lots of places are good mid range food so not worth a detour just to find them. I'd let them just see where they end up. It's pretty obvious which are just about feeding the hordes ; anywhere on La Rambalas for instance.