1. This file declares a class, `Player`, instantiates it, and assigns it to a global `player` variable.
2. The `Player` class contains four methods:
    - `constructor()`
    - `playPause()`
    - `skipTo()`
    - `setVolume()`
3. The `constructor()` method sets initial values for the `currentlyPlaying`, `playState`, `volume`, and `soundObject` properties.
    - `currentlyPlaying` is set to the first item in `album.songs`.
    -  The initial `playState` is `"stopped"`.
    -  The `volume` is set to the number `80`.
    -  The `soundObject` instantiates a new `buzz.sound` object using the `soundFileUrl` property of `this.currentlyPlaying`. The `buzz` variable doesn't appear to be initialized here, so presumably it's a dependency loaded elsewhere.
4. The `playPause()` method accepts one parameter, `song`. It sets it to `this.currentlyPlaying` by default. It checks to see if `this.currentlyPlaying` is different from `song`, and if so, it:
    - Stops the `soundObject` property.
    - Removes the `"playing"` and `"paused"` classes from the `element` property of `this.currentlyPlaying`.
    - Sets `this.currentlyPlaying` to the function's parameter, `song`.
    - Changes the `playState` property to `"stopped"`.
    - Instantiates a new sound object using `this.currentlyPlaying`, which was just updated to `song`.

   It also checks to see if `this.playState()` is `paused` or `stopped`. If it is `paused` or `stopped`;
    - `soundObject` property set volume with `setVolume()` and `this.volume` property.
    - Plays the `soundObject` property.
    - Changes the `playState` property to `playing`.
    - Removes the `paused` class from the `element` property of `this.currentlyPlaying` and add `playing` class.
   If it is not `paused` or `stopped`;
    - `Pause` the `soundObject` property.
    - Changes the `playState` property to `paused`.
    - Removes the `playing` class from the `element` property of `this.currentlyPlaying` and add `paused` class.
 5. The `skipTo()` method accepts one parameter `percent`. It checks to see if `this.playState` is not `playing`. If it's not;
    - return
    If it is;
    - `this.soundObject` set `setTime()` with `percent` dvivded by 100 and multiply with `this.soundObject.getDuration()`.
 6. The `setVolume()` method also take one parament `percent`.
    - Sets `this.volume` to the function's parameter `percent`.
    - `this.soundObject` set volume with `setVolume()` with `percent`.