This is a sixteenth note.
It lasts for one quarter of a beat.
There are four sixteenth notes in one beat.
There are 16 sixteenth notes in one bar of * time
When counting 16th notes, notice the different sound for each part of the beat – one ee and ah, two ee and ah… etc (written 1 e + a, 2 e + a… etc).
Once you are comfortable counting sixteenth notes on one note, apply them to the pentatonic scale, and then try the following pattern, which will help your picking technique.
Sixteenth notes are often used within a beat in conjunction with eighth notes, as shown in the following example. If you have trouble with the rhythms, practice them on one note until you are confident with them and then try the whole example. All the notes here are within the A minor pentatonic scale. Notice the use of staccato in this example.