This card game from 1898 by music publisher Theodore Presser was intended to be an educational aid to music students. The deck consists of 39 cards, which together form the basic chords possible for each of the 13 keys. Each card has a large letter in the middle, representing its note. The key to which that note belongs is in the upper right corner, and the musical symbol for that key (sharps or flats) is in the upper left. The bottom of the card lists all three notes in that key. The rules say that the game can be played as a simple set collection game like Authors, but is more interesting with a second set of rules, which it says resemble "Cassino". Each player is dealt a hand of five cards, and five more are dealt face up on the table. In turn, each player must if possible place a card from hand onto the table that matches the key of one of those showing. If unable to place a matching card, he may place any other card on the table. The player who puts the final card in a triad or chord collects all three as a set. If no cards remain on the table, the next player puts down any card to start the process over. When any player runs out of cards, one more card is dealt to each player. Once all cards have been played, the player collecting the largest number of sets wins. —user summary