JS Object Array Pagination

i need some help manipulating/paginating a JS array object by 5:

var musicItems = [
    ["assets/audio/1.wav"],
    ["assets/audio/2.wav"],
    ["assets/audio/3.wav"],
    ["assets/audio/4.wav"],
    ["assets/audio/5.wav"],
    ["assets/audio/6.wav"],
    ["assets/audio/7.wav"],
    ["assets/audio/8.wav"],
];

I want to know in JS the number of sets (2) and which elements belong to which set (set1->1-5, set2->6-8). Appreciate any help.