The base is original from the producer (chords and melodies), but is complemented with elements that complement the song that come from samplepacks, usually, vocal chops, guitars, wobbles sections, glitch effects. It is the standard in which most of producers work, in a project you will find MIDI files made by the producer, but also melodic loops.
Vocals downloaded from the free use splice .. the whole creation process was done by me
Sample pack Lofi Moods
Loop name OS_LFM_90_Fm_Smooth_Keys_Vinyl_Cut