Harmonic series, an Uncommon card

The card carries these facts from its Wikipedia article.

• Pitched musical instruments are often based on an acoustic resonator such as a string or a column of air, which oscillates at numerous modes simultaneously.
• As waves travel in both directions along the string or air column, they reinforce and cancel one another to form standing waves.
• Interaction with the surrounding air produces audible sound waves, which travel away from the instrument.

Rarity in WikiCards follows a year of Wikipedia page views: the most read articles become Epic and Legendary cards. The Harmonic series article was read about 110,000 times in a year. ATK comes from the length of the article and DEF from its quality, so this card hits with 67 and blocks with 44: each hit it takes is cut by 18 %.

Open packs. Each pack holds five cards drawn from real Wikipedia articles, the rarest last, and the fifth card is always Rare or better. The odds are shown in the game. A free pack arrives every hour and two can wait, and the Coins you win in duels buy more packs.

The cards just above and just below Harmonic series in the power ranking, all domains together.