If you want to do a PhD, wouldn't you just do a Masters rather than a second degree (not sure if I've misunderstood what you meant though!)?
Also, let me be the old sage here. I have a few friends who work for smaller high street law firms in London. They don't often make it home before 8pm.
I also have a few friends who are in investment banking and some who were in IB but have since moved on to working in private investment boutiques. I RARELY see them. They never leave the office before 10pm, though 2am is normal. They're also in the office on weekends. That means they have most of their meals at work. You will NOT have time for music no matter how adept you are at organisation and scheduling
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