PREFIX af: <http://purl.org/ontology/af/>
PREFIX event: <http://purl.org/NET/c4dm/event.owl#>
PREFIX tl: <http://purl.org/NET/c4dm/timeline.owl#>

SELECT ?start ?duration
FROM <http://dbtune.org/echonest/analyze-example.rdf>
WHERE
{
?e 	a af:StructuralSegment;
	event:time ?time.
?time	tl:start ?start;
	tl:duration ?duration.
}