The Apple Music site had a Try Now button up for desktop users all day, and clicking it opened iTunes. iTunes 2.1.2 if you were up to date. The problem was that Apple Music requires iTunes 2.2, and as late as 6 PM ET that wasn't available. If you clicked the Try Now button, iTunes would open and inform you that you needed iTunes 2.2 and offered an Upgrade button. That Upgrade button would take you to the web to download the old version of iTunes that didn't support Apple Music.
But nowhere in the tech press did you see mention of the botched launch. VentureBeat wanted to make sure you knew how not to get charged for Apple Music, as did Engadget and TheVerge. And TechCrunch thought things were "going pretty well so far" when, at 6:20 PM ET, some Mac users finally started getting the update ( seven hours after scheduled launch).
I tell them to turn to the study of mathematics, for it is only there that they might escape the lusts of the flesh. -- Thomas Mann, "The Magic Mountain"