Holding onto bass notes can be challenging. For simple in-chord stuff, you can normally fret the whole chord, giving you the bass note and plucking melodies in the chord per measure, before changing to the next chord. When the melodies start moving out of chords sometimes it becomes difficult to hang onto that bass note. Here are some options:
- More practise :)
- Don't hold onto the bass note play it staccato, but do it on purpose to make sure it sounds like an accent, not like "I couldn't hold the bass note".
- Rework the fingering so you can find a position to hold the bass note more easily.
- Rework the arrangement to something simpler you can play.
- Adopt a different technique that allows you to hold the bass note; for instance:
- Naudo Style middle finger bass note: for example, instead of playing a full first finger barre chord E shape or A shape, play the bass note with your middle finger. Ringy and pinky fingers can do normal stuff in chord leaving index finger able to play on or _behind_ the chord root position. (There are other features of this technique; it's not strength taxing, you can more easily mute strings in the middle of the fretboard, it is easy to pivot around your middle finger...not to mention your middle finger is pretty strong and normally "wasted" in a normal chord formation. Leaving your index finger, typically a very quick and agile finger, for "under chord" work is quite sensible.)
- Thumb over bass notes. I refer to this as bad technique, but it isn't really, it's a very handy technique :)