Here is a codepen:
http://codepen.io/KungFuPandemonium/pen/xOJyQW
Here’s my updateRecords function
function updateRecords(id, prop, value) {
if (value === "")
delete collection[id][prop];
else if (prop == "tracks"){
if (collection[id].tracks === undefined) {
collection[id].tracks = [];
}
collection[id].tracks.push(value);
} else if ( value !== "")
collection[id][prop] = value;
return collection;
}