Focus on this artwork and discuss the Composition.
The  Christ surrounded by angels stands against a golden background surrounded by black clouds. On his collar are the words Agyos Otheos (Holy God). The three precious stones which adorn the fibula of his mantle evoke the Holy Trinity: God the Father, God the Son and the Holy Spirit. With his crown and his crystal ball surmounted by a cross, he reigns over the Christian kingdom, both celestial and terrestrial. He is flanked by sixteen angels who sing (6) and play music (10). Their instruments are typical of the fifteenth century.
The scene was possibly inspired by the passage from the Gospel according to Matthew, which mentions: "When the Son of man comes in his glory, accompanied by all the angels, then he will sit on his throne of glory" ( Matthew 25: 31-46).
The central panel represents Christ blessing and looking down in the direction of the Virgin Mary, his mother, with three angels on either side. Each group of angels holds a large songbook. On the two side shutters, angels play musical instruments, five on each side. In the left panel the instruments are, from left to right, a psaltery, a tromba marina, a lute, a trumpet and a shawm. In the right panel, from left to right, there are a straight trumpet, a looped trumpet, a portative organ, a harp and a fiddle. The panels are  170 cm (5'6") high, thus the angels, or what we can see of them (the clouds obscure the part of their body below the knee), are life-size.
Many replicas of these panels have been produced.
Holy Spirit God the Son Trinity Holy Trinity  Christ Gospel according to Matthew God the Father Virgin Mary