Let’s face it: one of the most important parts of a song is its intro.

A memorable intro can bring lighters out of pockets, prompt roars of recognition from a crowd and cause freeway drivers to reach for the volume knob.

A great intro is also the first thing guitarists want to learn and the first thing they want to play when they enter a guitar store. We’ve compiled 20 of what think are the greatest rock and roll intros of all time.

Check them out, and then tell us some that you’d like to see on the list.

“Day Tripper,” The Beatles

Although George Harrison and John Lennon kick off this legendary single-note passage playing in unison, it was Lennon who actually came up with the riff. The part proved to be the perfect introduction for a perfect song, as the tune went on to become one of the Beatles’ most familiar hits upon its release as a single in December 1965. The part itself is quite simple and is performed in open position. Incidentally, the intro is also the basis for the song’s verse, interlude and outro chorus.

“Enter Sandman,” Metallica

If you like your music dark and heavy, you’d be hard-pressed to find any band that does it better than Metallica. “Enter Sandman” was the lead single from the group’s self-titled 1991 Black Album. The song’s intro is instantly recognizable, with the acoustic guitar sounding out a menacing one-measure pattern based around the key of E minor. Ironically, the signature sound is due in large part to the presence of Bb, the one note from the riff that is outside of the key. That note forms a tritone with the root pitch, E, providing the dissonance that is appropriate to

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