def mobileclient(username=None, device_id=None, *, token=None, locale='en_US'):
	"""Create and authenticate a Google Music mobile client.

	>>> import google_music
	>>> mc = google_music.mobileclient('username')

	Parameters:
		username (str, Optional): Your Google Music username.
			This is used to store OAuth credentials for different accounts separately.
		device_id (str, Optional): A mobile device ID. Default: MAC address is used.
		token (dict, Optional): An OAuth token compatible with ``requests-oauthlib``.
		locale (str, Optional): `ICU <http://www.localeplanet.com/icu/>`__ locale used to localize some
			responses. This must be a locale supported by Android. Default: `'en_US'``.

	Returns:
		MobileClient: An authenticated :class:`~google_music.MobileClient` instance.
	"""

	return MobileClient(
		username,
		device_id,
		token=token,
		locale=locale
	)