I would only download music if it has a store to process the transaction to buy the songs for say 99 cents each etc or full albums for like $8.99 etc USD and would retain all documentation of the purchase to prove legal right to own a copy of it. I am not familiar with those, other than this one clients son was using grooveshark and I think its the same as Limewire which is the grey area of music sharing. Grey = That is there is a mixture of legal and illegal downloads and even paying a small fee for membership does not make you immune to legal action against you for downloading what has not been approved for download etc.
I personally stay as far away from any music downloading sites as possible, mainly out of the fact that if I dont go there, then I cant get into trouble by say accidentally downloading something that appears as ok and later finding out that its not ok and illegal. Here in the USA, the law does not protect the dumb or those who assume legalities and are wrong! You cant claim I didnt know and sorry I wont do it again and just walk away. If your targeted for illegal activities your guilty until proven innocent! And fines and penalties are astronomical for those who have been tried for illegal downloads and ruined their lives paying fines equaling the cost of a house or more.
All the music I need these days I will either listen to streaming for free off of youtube with the youtube video window minimized or if I want it for listening to. And if it is so good that I need a copy of it to listen to outside of this youtube stream, I will go on amazon, ebay, or visit wal-mart and buy the actual CD and then when I get it I will use iTunes to create a MP3 copy of it so it can play on a MP3 player.
I have tons of music CD's and believe that if you want the music and want to stay out of trouble its best to have the CD in hand to prove that its yours to listen to etc. Same goes for my DVD movies that I converted to digital to play on my walkman when I travel. I own the physical copy of all movies that are digital so nothing illegal to worry about.
As far as the only downloaded music I have ever gotten other than from soundcloud promotion MP3's, Coke Rewards had some downloads as well as other food products where you enter a code and it allowed you to either cash in points or enter a 1 time use code from inside of a cereal box for a MP3 download of a single song that the manufacturer of the product paid the artist and record company for the ability to give you the customer the ability to have a MP3 of that song etc.
* Basically if you want to discuss download of music through shady sites, you are best not to ask about it here as for the Computer Hope Server & Site is based in USA and while members are from around the world, many also are in areas such as the USA where there are laws against aiding to piracy!
Lastly .... There are no sites that I know of that are 100% legit = legal that offer unlimited downloads. All the ones that offer unlimited downloads of music for even a monthly fee have legal problems that will be passed to you, especially if your in the USA or another country that abides by piracy laws. Most of these sites that are offering this service are dodging the law by hosting the music for download in countries that do not have anti-piracy laws or very lax laws.