Amazon-backed streaming music service Songza Media has introduced a new Music Concierge feature in an update to its free app for the iPhone and iPod touch. Songza is a free social streaming music app featuring a large collection of curated playlists organized for a wide variety of moods, genres, eras and cultural themes. The new Music Concierge service is designed to allow users to find and listen to music for specific situations based on time of…