I became father in september of last year. First couple of months are difficult, because you don't sleep well, but on the other hand, the baby sleeps a lot, so that leaves a bit of time to do on other stuff. Those first months not sleeping much aren't very nice, hehe, but we were lucky after less than two months she slept through the night and still does.
However, it's true that a baby takes quite some time and leaves less free time, but it's just an exercise in balance, basically. Ok, everything goes slower and there's less time to do certain stuff, but now and then I'll just say: now I'm going to record or listen to music or something. And sometimes the girlfriend says so and I take care of the baby. Or I'll just stay up after everybody else went to bed to do what I want to do.
What is the basic difficulty for me is going to (metal) gigs, since they come in waves, summer and winter are often calm, spring and fall there often are more gigs, so then the girlfriend doesn't like it that I'm often gone, but then, as happens now, the last gig I've been to is 2 months ago, since I don't do many festivals. Also, since I prefer gigs, I don't often just go to pubs anymore, therefore seeing some of my friends, with different musical taste, only every few months lately.
What is sometimes frustrating to me is that I sometimes in a short time get a lot of plans of things I want to try and do, but then there's no time to do it all immediately, so that even when I have done some of the stuff over a year, it seems like I've done nothing at all. And that happens as well, periods of lazyness...
When it comes to listening to music, that has changed since I live together with my girlfriend, has been so for 4 years now. She doesn't like most extreme music, so there's lot of headphone listening and just less listening than when I would live alone, for example. As for the baby: some people seem very afraid that letting a baby listen to extreme music is unacceptable, I call bullshit on that, however, I have noticed that while listening to some music with the baby around is no problem for her at all, a couple of records on a day is a bit much. Guess it depends on how sensitive your baby is. I remember listening to the Total Gape tape when she was just weeks old and she fell asleep, so no problem at all.
Last point: people often say a baby needs a lot of attention and that is totally correct, however I sometimes wonder whether it does really get better when they're a bit older (say 6-12 years), I mean if they need help with homework for school, I guess that's quite a time-sucker as well.
Anyway, to conclude this lengthy post: I never felt like I should drop certain things in total, but you have to be more picky, it takes longer and sometimes it feels a bit like a fight, since you have to search more for the time to do things.