Make the line answer the drums
Start with a few notes under a 909 groove. Slides and accents turn a simple bass pattern into a phrase with its own push and pull.
Perform the filter
Cutoff, resonance, envelope and drive move the line from restrained to urgent without replacing the MIDI you wrote.
Build the next section
Copy the Part, change the accents or filter movement and hear the bassline develop across the Arrangement.