Whilst "jumping" between strands does occur, it takes more energy to do so, so electrons have a tendency to take the easy route and stay within a single strand in low power situations, i.e. until such a time that the signal is so strong that all the "free spots" into which electrons can jump within their strand are filled and it is no longer possible to move within a single strand because all available spots are filled, at which time electrons will be attracted to, "or jump" to available locations in another strand
Consider the each strand will have valence electrons freely moving around in them creating free spots, such that IF the strands are too thin to "accommodate" the amount of energy being transferred, then electrons in each strand will try to transfer to another strand - the "jumping" then causes the wire will heat up, which introduces noise into the signal
Having said all of that - in the audio world the signal is AC and as such the electrons just tend to "shuffle around" and does not "travel" in any given direction
Whereas in DC circuits, the electrons do flow in one direction, but very slowly, whereas the flow of energy is "instantaneous", i.e. almost the speed of light
How fast does electricity flow? - BBC Science Focus MagazineRegards