If you are in a relationship, or any kind of friendship, then that can be in the top tier: something you live for. It can be in middle tier as well: something that sustains you. If it is in the bottom tier, then it is a bad relationship, of course. Most good relationships have to have elements of tiers one and two. Instinctively, without even thinking about it, I put my love relationship on the top tier, as something valuable in an of itself, not as something with a merely utilitarian purpose.
I think happiness is the wrong goal. The goal should be doing as much in the top tier as possible. So it's not that music or love make me happy, but that these things are happiness.
Many things serve a dual purpose: they are ends in themselves and are also sustaining and enriching. Friendship is one such thing. The more hours devoted to tiers one and two, the better.