In WiMP for iPhone and iPad you can easily group your favorite music. Search for an artist or album, starmark the artist, album or track and that's it.
Press the button "Favorites", then you can select Favorite artists, Favorite albums or Favorite tracks. Press Favorite artists, then you get an entire list of all your favorite artists. Press one artist, e.g. Colin James, then you get the entire list of all his albums. Press one of the albums, then you see the tracks and you can listen to the album or a single track.
That is a perfect way to create your own selection of your favorite artists and music, much much better than the playlist thing in Spotify, which is only good, if you just want to create a list of e.g. partymusic.
With the favorite artist feature Spotify could work like my own cd collection and almost replace it.