Malicious Melodies

When Malicious Melodies enters the battlefield, you may pay {x}. If you do, tap up
to X target creatures and put a -1/-1 counter
on them. Those creatures don't untap
during their controllers' untap steps for as
long as you control Malicious Melodies.
At the beginning of your upkeep, pay X life
or sacrifice Malicious Melodies.