Composer of Spring is a rare Creature — Satyr Bard card from Commander Masters (CMM), collector number 739. Current market price: $7.21, TCGplayer market prices via Scryfall.
Constellation — Whenever an enchantment you control enters, you may put a land card from your hand onto the battlefield tapped. If you control six or more enchantments, instead you may put a creature or land card from your hand onto the battlefield tapped.