Excerpt:
In this tutorial series we will learn the classical guitar technique called "tremolo". Essentially this technique mimics the way a violinist keeps a note "alive" and continually ringing out. The idea is to get your picking fingers moving so smoothly, evenly and efficiently that it sounds as if it is a continuously "singing" note. Eventually we want to be able to make these notes sound together seamlessly and even rise and fall in volume & dynamic level gradually.

For this (and all classical guitar pieces) lesson we will refer to our right hand fingers as such:

Thumb - "p"
Index - "i"
Middle - "m"
Ring - "a"

Start by plucking the bottom E-string with your thumb. Then "roll" your fingers over the top E-string one at a time with your ring finger, then your middle, then your index.