When you're choosing earplugs, you want decibel reduction and attenuation of the signal. Simply blocking sound out is fine, but you're gonna be more likely to pull your earplugs out of your ears because you cannot hear everything. If you utilize plugs that attenuate the decibel level, you'll be more likely to keep wearing them.
This is true for live music concerts and if you're playing in a studio or other situation with a band.
Please protect your ears. If you damage them, you cannot repair that damage. Your ears are very, very important.
If you're looking for good earplugs, I suggest Eargasm or Earasers. Both will offer what I speak of, here.