How to Compose a Good Bassline

Composing a simple bassline

Find the roots of the chord on the bass instruments or write them out on a bass clef with the melody and chords.

Repeat. From this point, a punk bassline is almost automatically made by playing repetitively on these notes. To ensure a more interesting line though, it is first useful to smooth out the bassline.

To smooth out the bassline, use scales or small jumps to connect the chords together. Don't be afraid to invert the chords, or change what note in the chord is on the bottom, to make the line smooth.

Check the melody. See if it sounds independent of the bassline. Try to use contrary motion, such as when the melody goes up, then the bass goes down and vice versa.

Advancing the bassline

At this point, this is a simple bassline. This may do for some, but the more creative will want to embellish.

Experiment with rhythms to get a groove going.

Take the other notes in the chord or tones close to the original note and play those once in a while. Be sure to focus on the main note though.

Let the bassline complement the other parts. If this has a riff, the bass would love to have its turn with it. Just don't make it a carbon copy of another part, or else the bassline should take the bus home!

Winging it

Find out what chords your guitarist is playing.

Repeat those notes in time with the guitar. Keep experimenting until you are comfortable.

Using the notes you were already playing as a base, add different notes to create a melody. Keep experimenting until you find something that sounds good.

Take on board constructive criticism from your bandmates. It's very important that you work together and put in equal amounts of effort.