Question
 

Would I benefit more from listening to "classic" bands and listening to several bands from every 'era' over the past 50 years, or modern Indie bands?

i'd say classic, because knowing the history/development of music can help you better understand it as a whole

You will definatly benefit from listening to a more diverse range of music than sticking to one type of genre. I quite often discover new music from decades gone by that that lead onto a direction for my music tastes.

Honestly I think this is a stupid question. Just listen to what you like, what's the point in forcing yourself to listen to music you don't enjoy?

i think that listening to tons of artist from the exact same genre will get alot more stale than digging to the roots and hearing how the music has evolved over time. like dreadnaught said though, if you dont like something dont listen to it.

listen to what ever YOU think you will benefeit from not what other people think you will...cause then you wont benefeit from it.