Apple TV deliveries start tomorrow, October 30th, but it won't support using Siri voice commands to find songs on Apple Music—at least not yet. Apple said the feature is coming, but won't be available until early 2016.
Siri can't search Apple Music on your new Apple TV until next year
The new Apple TV supports streaming TV channels and other content from networks, streaming music, Netflix, Hulu,and the iTunes Store. It also supports Apple Music, along with third-party apps including games, and includes a redesigned Apple TV remote with gesture-based navigation, and support for Siri voice commands.
Those Siri commands let you search for TV shows and movies, but won't do the same for music. That's going to change at some point in early 2016 when Apple TV gets a software update with Siri for Apple Music support. Apple told Buzzfeed the update is coming, but didn't narrow down when that's happening other than to say early next year.
Searching for music with Siri on Apple TV could make Apple Music more enticing for people on the fence about whether or not they should pay for a monthly subscription. Apple gives subscribers their first three months for free when they sign up, which led to 6.5 million paying customers when the first wave of trials ended.
Siri Apple Music search support will come as a free software update, but for now we'll have to wait until next year.