```js
const tracks = require('express').Router();

//...

// The root router for requests to our tracks path
track.get('/', function(req, res, next) {
  let albumId = req.params.albumId; // Our problem line

  // retrieve album's track data and render track list page
});

// The route for handling a request to a specific track
track.get('/:trackId', function(req, res, next) {
  let albumId = req.params.albumId; // <-- How do we get this?
  let trackId = req.params.trackId;

  // retrieve individual track data and render on single track page
});

//...

module.exports = tracks;
```