How to Compose Music

First, you need a good rhythmic brain, as the beats (either heard or non-heard) are the thing which makes a bunch of random notes musically beautiful, try tapping your hand or foot, (counting 1,2,3,4,1,2,3,4) or if you prefer without counting when hearing your favorite songs, keep it at a steady rate, first do it slowly, then fast (most songs are on 4 beats) if your counting is not syncing with the song, then it’s possible it’s on 3 or 6 beats, in that case please change the song :)

Second, you need to know some basic chords or scales, (C, D, G major and minor will be a good start) in fact if you are using a keyboard all the white keys becomes part of C Major scale (easy isn’t it ? :) ) so all you need to do is play some random keys according to your internal rhythm or by using a metronome, ( using a metronome all the time is not a good idea ) always use foot tapping to make the internal rhythm perfect, then hit the keys either 1 time for a beat, or 1 time for two beat, mix it with rests (non-playing) for 1 or 2 beats or hold the key for full 4 beats, most common method is to play a chord with one hand and play single notes with the other, independent hand play takes few months to learn, and for fast stuffs it will take more months

Third, learn few more scales apart from major, minor scales, like pentatonic, or blues scale, now play random keys in any one of the scale, concentrate to stick with the notes in the scale, with the above method, identify a pattern which sounds good to you, then memorize it, add more octaves of the same scale, add another couple of notes to the pattern, and continue the process, record the MIDI if possible, and overtime as your fingers gets going fast, your brain will become good in this and it will all began to come naturally

from my experience, it will take around 2months of 2hr practice (daily) for all these things to work properly on a keyboard/piano

note that the music is managed in right hemisphere of the brain, so if you are right handed person (more active left hemisphere ) then you should work to activate your right hemisphere more, by doing activities like, drawing anything with your left hand, tapping/beats on your desk/chair with your left or both hands, doing other regular things with your left hand, like brushing, phone etc… and if possible learn to meditate, read stories/books to activate your imaginations (right hemisphere), hear more classical music etc.

between you should also learn other easy songs, and you can improvise on those methods/patterns learned to create your own song changing notes or rests

alright then, Happy Composing :)