The bass is usually a complimentary voice in pop music. Usually, but not always, the bass guitar serves to propel the music along in the background of a song to create necessary rhythmic counterparts between the drums and the guitar. To listen to a bassline by itself seems a bit strange, but in its proper context a good bassline is a terrific thing. Here is an example of what a walking bassline sounds like. This is roughly the main bass lick that Geddy Lee plays on the Rush song "Limelight." The secret to why this is such a good bassline is how it "walks." This song is in the key of E major, and Lee walks up the E major scale at first, and then follows two chords the guitar is playing, the B and A major chords. Except that while the guitar is playing those two chords, Lee elects to play an arpeggio of them, playing the root, the fifth, and then the octave. Simply by "stretching" those chords Geddy Lee makes the song much more interesting and complex.
There is certainly a trick to walking bass, it isn't something that everyone can do, and it is certainly something that requires practice and a good ear. It is the kind of thing that rewards knack over proficiency. Writing good basslines is an art -- Cindy Lee Haddock wrote an article on how to do it here.