The Alto Recorder is the soloist of the family, and is the instrument most often associated with Baroque recorder works. We should think of this instrument, and not the Soprano, as the primary voice in the family. It has a clear voice and can be heard in all but the thickest contexts.
One note, in the UK the Alto Recorder is known as the Treble Recorder.
Telemann Sonata in F minor on Alto Recorder
Greensleeves to a Ground on Alto Recorder