RunBeat,
If you are identifying songs using track/upload or song/search, then you should have song IDs (SO..., SO..., etc.). You can get multiple audio summaries at once using song/profile.
e.g. http://developer.echonest.com/api/v4/song/profile?api_key=API_KEY&format=json&id=SOATBBX1311AFDC272&id=SOBTLUJ1315CD4A54B&bucket=audio_summary
David