This is a great little tool for practicing your strumming patterns and increasing your speed in a controlled way.
A metronome is a practice tool that produces a steady pulse (or beat) to help musicians play rhythms accurately. The pulses are measured in beats-per-minute (BPM). Most metronomes are capable of playing beats from 35 to 250 BPM. Common uses of the metronome are helping you to maintain an established tempo while practicing, and learning difficult passages.
The first step in metronome use is to understand time signatures. Time signatures are found at the beginning of a musical piece, after the clef and the key signature. Time signatures (also called meter signatures) consist of two numbers. The top number indicates the number of beats in a measure, while the bottom number corresponds to the value of the beat. Most often, you will see 2, 3, 4 or 6 beats per measure. Beats are commonly half notes (the bottom number of the meter signature is “2”) or quarter notes (“4”) (the bottom number of the meter signature is “4”).