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 `this.playState` is equal to `"paused"` or is equal to `"stopped"`:
    - It will set volume of `this.soundObject` to `this.volume` from the `constructor` method.
    - It will play the `this.soundObject` property
    - It changes `this.playState` property to `"playing"`.
    - It removes the `"playing"` class from the `element` property of `this.currentlyPlaying`, and adds a class of                   `"playing"`.
If the above conditions don't evaluate as true then:
    - It will `pause` the `this.soundObject` property.
    - It changes the `this.playState` property to `"paused"`
    - It removes the `"playing"` class from the `element` property of `this.currentlyPlaying`, and adds a class of `"paused"`
5. The `skipTo` method takes `percent` as a parameter.
If `this.playState` is not equal to playing it will `return`
    - `this.soundObject` with use `setTime()` and take the parameter `percent` divide it by 100 then multiply it by `this.soundObject..getDuration()`
6. the setVolume method will take a single parameter `percent`
    - it will set `this.volume` equal to the `percent`
    - it will then `setVolume` using `percent` to `this.soundObject.