
Cumulative upkeepCumulative upkeepAt the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
: Put a music counter on target creature. If it doesn't have "At the beginning of your upkeep, destroy this creature unless you pay
for each music counter on it," it gains that ability.
Hover an underlined rule to see what it means.
Read from the rules text. A card that enables a keyword makes or is the thing; a card that rewards it gets better when you have it. Two cards interact when one enables what the other rewards.