SPARQL query on the remote remote endpoint RDFLib / Redland

I'm trying to query remote endpoints and get get owl:sameAs mappings, I've tried both RDFLib and Redland but neither worked for me, probably I'm not dealing with namespaces correctly.

Here is my attempt in RDFLib:

    import rdflib

    rdflib.plugin.register('sparql', rdflib.query.Processor, 'rdfextras.sparql.processor', 'Processor')
    rdflib.plugin.register('sparql', rdflib.query.Result, 'rdfextras.sparql.query', 'SPARQLQueryResult')

    g = rdflib.Graph()

    query = """
        SELECT *
        FROM <http://api.talis.com/stores/bbc-backstage/services/sparql>
        WHERE {
             ?s a http://purl.org/ontology/mo/MusicArtist;
                http://www.w3.org/2002/07/owl#sameAs ?o .
        }Limit 50
    """

    for row in g.query(query):
        print row

And here is Redland:

import RDF
model = RDF.Model()

query = """
    SELECT *
    FROM <http://api.talis.com/stores/bbc-backstage/services/sparql>
    WHERE {
         ?s a http://purl.org/ontology/mo/MusicArtist;
            http://www.w3.org/2002/07/owl#sameAs ?o .
    }Limit 50
"""

for statement in RDF.Query(query ,query_language="sparql").execute(model):
    print statement

Can you please give a hint what is wrong in any one of those? Yet another difficulty I have: Is it possible to get dataset name of the object? For example: if there is:

?s = http://www.bbc.co.uk/music/artists/eb5c8564-927d-414d-b152-c7b48a2c9d8b#artist
predicate = http://www.w3.org/2002/07/owl#sameAs
?0 = http://dbpedia.org/resource/The_Boy_Least_Likely_To

Can I get name of the "Dbpedia" in this example? Or any other dataset to which I'm having sameAs link? (Or probably I could just look-up interested dataset names in the object string) thank you very VERY much in advance