I think many teachers of music composition train their students to create "sticky" melodies (something that are memorable, even unforgettable). One of the melodies I think demonstrates stickiness is James Brown's melody for "Please, Please, Please." 
I'd love to hear if you find this melody especially memorable. What techniques does Mr. Brown (!) use to create the stickiness.
Here are just a few of the things my students and I have listed as the elements of stickiness...

• repetition of lyrics, articulations, pitches, form and rhythms
• exaggeration of dynamics, rhythms, articulations, pitches high & low
• surprising intervals, rhythms, articulations, dynamics, harmonies, silences
• economy of different melodic, rhythmic, harmonic ideas

What do you think? 

I've been on a music tour bus for more than four weeks playing Christmas music with pianist Lorie Line. Someday, I'll post her music but it is now Epiphany, and I am in a self-reflective mood and this music suits me.
This particular composition by Pärt steadies my breathing at first and like Samuel Barber's Adagio for Strings raises my temperature ever so slowly until I find that there is a pounding in my chest. 
Pärt's compositions mirror one's meditation on resounding bells, tintinnabullations. This music centers around the focus you bring to the listening experience. If you've never heard it, do yourself a favor -- pause...calm your mind and body...close your eyes...concentrate your breathing...focus on your heart beating...and you will be rewarded.