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`.
    - if the `playState` property is either `"paused"` or `"stopped"`, it:
    -   Sets the volume of `soundObject` property to volume 80.
    -   Plays the `soundObject` property.
    -   Changes the `playState` property to `"playing"`.
    -   Removes the `"paused"` class from the `element` property of `this.currentlyPlaying` and adds the `"playing"` class.
    - if the `playState` property is neither `"paused"` nor `"stopped"`, it:
    -   Pauses the `soundObject` property.
    -   Changes the `playState` property to `"paused"`.
    -   Removes the `"playing"` class from the `element` property of `this.currentlyPlaying` and adds the `"paused"` class.
 5. The `skipTo` method accepts one parameter, `percent`. If the `playState` property is not `"playing"`, it:
    - returns `this.soundObject.setTime( (percent / 100) * this.soundObject.getDuration()) `.
    - It sets the time of the  `soundObject` property to a percentage multiplied by the `getDuration() method`.
 6. The `setVolume` method accepts one parameter, `percent`. It sets it to `this.volume` by default and sets the volume of the `soundObject` property.