Apple will make iOS 8.4, the upgrade necessary to try out the Cupertino, Calif. company's new streaming music service, available early Tuesday for downloading to iPhones and iPads.
Ian Rogers, director of Apple Music, mentioned an 8 a.m. PT (11 a.m. ET) kick-off for iOS 8.4 in a since-revised blog post. Beats 1 -- the online radio component of Apple Music -- will also debut Tuesday morning.
Macs and Windows PCs will have to upgrade to a new version of iTunes -- also expected tomorrow -- to listen to Apple Music. Although Apple has pledged to release an app for Google's Android, that will not appear until later this year.
Customers can try Apple Music during a three-month free trial, but once that has expired they will have to pony up $9.99 per month for an individual subscription or $14.99 a month for a family plan. The latter allows for up to six separate members.
Beats 1 will be available free of charge to anyone with an Apple ID, the credentials Apple device owners use to connect with iCloud.
The iOS 8.4 and iTunes upgrades will likely reproduce some of the same effects as a new edition of the iPhone operating system: Large numbers of users simultaneously trying to grab the bits, slowing down or stalling Apple's servers.
According to Rogers' original post, Beats 1 is to go on the air at 9 a.m. PT (noon ET).