You don't always have to pluck a note to play it. Hammer-ons and pull-offs are techniques that let you play some notes using only your left hand. They are useful for playing quick bass licks and slurred notes, and you'll hear them in many songs.
What is a Hammer-On?
A hammer-on is a note you play by "hammering" a finger of your left hand down onto the string while it is still vibrating from a previous, lower note. This changes the pitch up to the new note. You don't pluck with your right hand; the sound comes from the vibration that is already there, aided a little by the force of hammering your finger against the string.
Playing a Hammer-On
To play a hammer-on on the bass, first play an ordinary note. With your first finger, play the sixth fret on the second string (the D string), a G♯. Now, use your third finger to quickly and forcefully slam down on the string at the eighth fret. If you do it right, you should hear the pitch go up to an A♯ without any major loss in volume.
You can also play a hammer-on with your second or fourth finger. You don't have to start with your first finger, either; you can start with your second or third finger, or an open string.
If it didn't seem to work quite right, here are several things to keep in mind:
- Slam your finger down quickly. If you are too slow or don't use enough force, your finger may mute the string a bit before pushing it all the way against the fret.
- Don't hurt yourself. While speed is necessary, you can overdo it. Try hammering on lightly to get a sense of just how much force you need, and don't use much more than that.
- Have good aim. If you don't hammer directly on the string, the note could buzz or be muffled.
- As with any bass note, use the pad of the finger. Don't use your fingertips like a guitar player.