Stir It Up by Bob Marley is a relatively easy song for beginers – there are 3 parts to learn (though the two bars you need to play in the intro are also present in the chorus!).
I class this as a Level 4 bass line (mainly because of the 16th notes in the line). (The scale I use is 1 to 10 – a Level 1 bass line might be a predominantly half note ballad kind of line like Imagine and a Level 10 line would be an uptempo 8th note based line like I Saw Her Standing There or Shake A Tailfeather). The easiest way to learn this rhythm is to use the ‘mental representations’ method – without going into great detail follow the? notation with the bass line, imagine the bass line is a melody (it is pretty melodic) and hum it to yourself. When you can hum the rhythm then learn the note locations on your bass out of tempo. Then put those note locations into the ‘melody’ that you created from humming the bass line.(Side Note: this is exactly how they get 4 and 5 year old kids started with classical piano and violin in the Suzuki Method).
Stir It Up starts with an 8 bar intro, the bass comes in for only the last two bars of this section.? Then there are repeating sections of chorus and verse: