A metronome is an important practice tool that every musician should have. When it comes to choosing a metronome there are many, many options. If you have never been in the market for a metronome before it can be hard to decide which features are most important. Two features that I have found to be indispensable in my practice sessions are 1) a sound that is loud enough to be heard over my playing and 2) some sort of visual marking of the beat, usually a blinking light, in case I can’t hear it.
The metronome I keep on my piano is an ancient Dr. Beat I bought in the 80s. I like it because I can usually hear it even when I’m singing high notes (I’m a singer by training), it can create endless subdivisions of the beat, I can adjust the meter of the beat and make the downbeat louder than the rest of the beats.