Hi! This is an important question for people who like HipHop, meaning Old School Boom Bap. Old School Boom Bap is typically around the tempo of 85 bpm and faster, so if you can remember this tempo, if you can clap it with your hand or snap it with your fingers, you could do your own freestyle rap session with the typical Hiphop-Tempo. If you measure the length of one bar having 4 beats in the tempo of 85 bpm (beats per minute), you will see that it is approximately 2 seconds and 69 microseconds long. If you have a song that has 80 beats that are this fast, you would have twenty bars (80 divided by 4) with the speed of 85 bpm.
If you multiply 80 (beats) with the duration of 2.69 (seconds), you receive 215.2 (seconds). This are three minutes and 20.2 seconds.
There are lots of good songs that take around three minutes, so now you know, if you take twenty 4/4 bars in a speed of 85 beats per minute (bpm), or 80 beats at all in that speed, you receive a song length of a little bit more than three minutes, giving you a convenient song duration that can be very entertaining and is a good orientation length for your own songs, which you can take no matter which music style you are making beats in!
In order to measure the bar durations yourself, you need a metronome (app) and a stop watch (app).
Quick-Fix for memorizing music tempo:
If you want to get used to the different music speeds (tempo), also by memory, you can take a watch or a timer and let the seconds count. If you take two even beats for one second and count them loud or clap them with your hands (or snap them with your fingers) while the seconds go by, you get a song speed of 120 bpm. You can also use more seconds and take more or less beat tempo for this time space and test out the beat tempo that you imagine or shout out loud or clap with the hands while letting the seconds go by. Like this you can get a feeling for the different tempos and practice different speeds without having a metronome with you. But keep in mind: if you count slower it will take more repeats of seconds going by.
For example:
●——●——●——●——●——●——●0 ½ 1 1½ 2 2½ 3 ← Seconds
●——————●——————●——————●——————●——————●——————●0 1,5 3 4,5 6 7,5 9 ← Seconds
You see, if you clap your hands twice a second with even duration (each clap is exactly the half of a second) the repeats are less to finish the cycle as if you take longer to clap in your hands again, in the second diagram using a tempo of 40 bpm.
If you have questions and/or liked the article, please leave me a comment below!