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.
Process note
There is made from scratch guitar melody alongside with synth loop and adlibs loop.
Melodic loops
Instrument Main Sample
Sample pack Origin Sound - Vintage Vinyl
Loop name OS_VV_90_C#m_Bedtime_Synths_Vinyl_Cut