This is a school physics lecture, prepared for the Pakistani intermediate part II syllabus, chapter 14 on simple harmonic motion. It is not made for a general audience and it looks it — whiteboard, diagrams, no production. That is also why it is useful.
Most cymatics video shows you one apparatus in isolation. This works through three in sequence — the flame tube, the plate, the acoustic levitator — and derives each from the same account of nodes, antinodes and resonance. If you have built rigs by copying other people's builds and never sat down with the standing-wave maths, sixty-eight minutes here will connect the things you already have on the bench.
Be aware of the register: it is exam-oriented, so definitions, construction and working principle are covered in the order a marker wants them, not the order a builder would choose.