Flaws in other people's theories time!
1) "Go back in time, steal the original, working time machine." You don't know where it was invented or when. No go. If you did research, you might be able to go back in time and make a deal for him to MAKE you a new one, while he observes your sort-of-working end product that might help accelerate his research. But still, doesn't solve the 'dunno when / where' problem.
2) Going back to the Big Bang is a very, very, very, very bad idea. Let's see why!
a) Explosive decompression.
b) You have the entire Universe's energy being popped into you all at once. Ouch. Later on, if life ever achieves sentience and manages to develop astronomy, they'll be puzzled as to why one side of the Universe has a crumpled edge (even though your body wouldn't provide much resistance at all, you'd still cause SOME, and over billions of years that would begin to show).
c) Gravity. That speck is the entire Universe in one tiny pocket. You'll be crunched into nothing because of matter attraction.
d) You don't know exactly when it occurred. Sure, we have estimates, but that estimate's in the range of MILLIONS OF YEARS. How dumb would you feel when you go back too far and spend your entire hour in your multi-billion death-escaping suit watching absolutely nothing at all? The one dot of existence would be microscopic and you wouldn't even know which way to look.
In conclusion, don't do that. If you want to do something FOR SCIENCE, go back and get live dinosaurs / pre-cambrian sea life / trilobytes / whatever. I'd personally want to find the first multicellular organism and document it but there's no way to know when and where for that one, so I'd have to settle with species that have long gone extinct.
And besides, how epic would it be to ride a trained triceratops / anklyosaurus / whatever around? (Take it from soon after hatching, train it, manage to avoid being killed by parents as there's evidence they were nesting creatures.)
I can find no flaws in people wanting to go back and enjoy music live they weren't old enough to. You lucky, greedy buggers.