Three are recognisable instruments: in the background on the left, there is the keyboard of a cordophone of the viola da mano family; in the centre of the canvas, hanging from the shoulder belt of the kneeling shepherd, a soprano crumhorn; in the foreground, to the left on the ground, a phagotus. The presence of this last instrument is particularly unusual piece of documentary evidence.
The phagotus was a particular type of wind instrument with a double reed, operated with a bagpipe mechanism which produced polyphonous music with a wide range of dynamics and tone.
The phagotus was invented by Afranio degli Albonesi da Pavia, a canon in the service of cardinal Ippolito I d'Este and, after his death in 1520, of Duke Alfonso I. The history of its invention, with a picture of the instrument, was recorded in the Introductio in Chaldaicam linguam written by Afranio's nephew, Teseo Ambrogio degli Albonesi, and printed in Pavia, by Simoneta, in 1539. According to Teseo Ambrogio, the instrument was first produced in Ferrara around 1521 with the help of the skilled court wood-turner Giovanni Battista Ravilio after a series of apparently unsuccessful experiments. Afranio himself was a virtuoso player of his instrument.
The depiction of the phagotus discovered in the Maestro dei Dodici Apostoli painting is of great documentary significance. It confirms that the artist was a frequent visitor in court circles. The presence of the instrument in a typical pastoral setting also establishes a hitherto unknown context. Rather than a precursor of today's bassoon, the phagotus was a refined version of the bagpipes which conjured up the courtly image of bucolic life so popular with the cultivated audience of eclogues and pastorals at the d'Este court.