Playlist in the parameter songs

You certainly can name the argument and the parameter the same thing, nothing prevents you from doing so.

The reason why that was not done in this code is likely for two reasons:

1. To make it clear that arguments and parameters are not linked based on their name. It's pretty common that people that start out with coding think that arguments and parameters have to be named the same thing to work.
2. To make it more clear that the argument and parameter are not the same variable. In other words when you call a method with an argument what is passed is just the value stored in the variable, the variable itself is not passed. Meaning that changes to the parameter variable does not reflect back to the argument variable. Which is something people might think will be the case if they are named the exact same thing.

Basically take this code:

var message = "Hello";

function test(message) {
    message = "World";
}

test(message);
console.log(message);

If you knew nothing about arguments and parameters it would not be too unlikely that you would guess that the argument gets assigned to the parameter based on them sharing the same name. And that the variables are linked such that when message is assigned a value within the test function that will result in the message variable outside the function to change as well.

I've seen many students have that exact misunderstanding about arguments and parameters, so going out of your way to avoid that confusion is sensible for a teacher.

But if you changed the code for this lesson into this:

 var playList = [
    ['I did it my way', 'Frank Sinatra'],
    ['Respect', 'Aretha Franklin'],
    ['Imagine', 'John Lennon'],
    ['Born to Run', 'Bruce Springstein'],
    ['Louie Louie', 'The Kingsmen'],
    ['Mabellene', 'Chuck Berry']
];

function print(message) {
    document.write(message);
}

function printSongs(playList) {
    var listHTML = '<ol>';
    for (var i = 0; i < playList.length; i += 1) {
        listHTML += '<li>' + playList[i][0] + ' by ' + playList[i][1] + '</li>';
    }
    listHTML += '</ol>';
    print(listHTML);
}

printSongs(playList);

Then it would still work perfectly fine.