Invalid Parameter Bucket on songs call

The following call...

http://developer.echonest.com/api/v4/artist/songs?api_key=<api_key>&id=ARYML1P1187B9AF39B&format=json&start=0&results=100&bucket=id:spotify

is giving me an Invalid parameter: bucket error. The docs clearly state that using bucket in a songs call will reduce your results to those songs that are available on that service. Has there been a change in the API? Here is my result...

{
    "response": {
        "status": {
            "version": "4.2",
            "code": 5,
            "message": "method - Invalid parameter: \"bucket\""
        }
    }
}