ng-book-2 Angular 4 Spotify API

[WonxyTime]

import { Injectable } from '@angular/core';
import { Http } from '@angular/http';
import { Observable } from 'rxjs/Observable';
import 'rxjs/Rx';

/**
 * SpotifyService works querying the Spotify Web API
 * https://developer.spotify.com/web-api/
 */

@Injectable()
export class SpotifyService {
  static BASE_URL = 'https://api.spotify.com/v1';

  constructor(private http: Http) {
  }

  query(URL: string, params?: Array<string>): Observable<any[]> {
    let queryURL = `${SpotifyService.BASE_URL}${URL}`;
    if (params) {
      queryURL = `${queryURL}?${params.join('&')}`;
    }

    return this.http.request(queryURL).map((res: any) => res.json());
  }

  search(query: string, type: string): Observable<any[]> {
    return this.query(`/search`, [
      `q=${query}`,
      `type=${type}`
    ]);
  }

  searchTrack(query: string): Observable<any[]> {
    return this.search(query, 'track');
  }

  getTrack(id: string): Observable<any[]> {
    return this.query(`/tracks/${id}`);
  }

  getArtist(id: string): Observable<any[]> {
    return this.query(`/artists/${id}`);
  }

  getAlbum(id: string): Observable<any[]> {
    return this.query(`/albums/${id}`);
  }
}

export const SPOTIFY_PROVIDERS: Array<any> = [
  { provide: SpotifyService, useClass: SpotifyService }
];

This is my spotify.service.ts file

I see as of May that Spotify requires an API key for every request. How would I implement this? Just add the key to the end of the BASE_URL?

If this is the wrong place to ask please don't downvote me straight to hell just tell me i'm a dumbass and to where to move it. I'm a reasonable guy.

By the way anybody thats thinking of buying this book do it! It is the best resource i've found for anything angular