How it works
A 42 BPM metronome is Largo in Wikipedia's list of tempo markings (40 to 66), and 42 is where a 19th-century French dial pictured in German Wikipedia's Tempo article begins its Largo band. Both articles describe their figures as approximate.
Read the full guide
Start
Tap the pad, or press Space, and wait: at 42 the second click is a long time coming. Every click matches and the pad shows two equal dots, so no bar is marked. Tap again to stop.
Change the tempo
Tap the number under the pad and type a new tempo, or nudge it with minus and plus. Type 84 for double time: like 42 it is a notch of the most common wind-up scale in Wikipedia's Metronome article, where 42 comes second, straight after 40.
Questions and answers
Does grave go as fast as 42 BPM?
Not in Wikipedia's list of tempo markings, which stops Adagissimo and Grave at 40 and gives 42 to Largo and Lento. A present-day Japanese dial pictured in German Wikipedia's Tempo article carries Grave on to 44, which puts 42 in the middle of its band.
Do all metronome dials start their tempo words at 40?
Two of the three pictured in German Wikipedia's Tempo article do: a present-day Japanese dial opens with Grave at 40 and a 20th-century German one with Largo at 40. The 19th-century French dial prints no word until 42.
Is dotted quarter = 42 the same as eighth note = 126?
Yes, by our sum: three eighth notes to each dotted quarter make 126 a minute. This site's 6/8 metronome counts the dotted quarter, so type 42 there and it ticks every eighth note too. If your 42 counts eighth notes, type 14.
How slow is 42 beats per minute?
Seven clicks every ten seconds, by our sum. A bar of 4/4, unmarked here, would take 5.71 s. Half a beat, the eighth note, is 714.3 ms; a quarter of one, the sixteenth, 357.1 ms. The dotted eighth outlasts a second: 1,071.4 ms.
Why can't I hear the metronome?
At 42 the gap between clicks is long, so count to two before blaming the phone. Then look at its ring switch, its volume and any Bluetooth speaker. Sound or no sound, the pad's two dots change over on each beat.