Seifert surface
https://en.wikipedia.org/wiki/Seifert_surface for a specific mathematical knot with seven crossings (denoted 7_4 in the classification table for knots
https://en.wikipedia.org/wiki/Knot_(mathematics)). An artist's impression of a wind instrument... not; phantomic mask... not.
The engineer:
Thanks to Steven Charlton who used "Seifertview" by Jack van Wijk to produce the corresponding stl file which then was solidified in Blender.