Rock Band 4 requires $20 adapter to use last-gen instruments on Xbox One, but not PS4

Rock Band 4 players on PlayStation 4 and Xbox One will be able to play the music game with their closetfuls of old PlayStation 3 or Xbox 360 instruments, respectively. But Xbox gamers will have to pay more to do it, developer Harmonix Music Systems announced today.

Harmonix is now accepting pre-orders for the stand-alone retail version of Rock Band 4, which is meant for people who want to play the game with their existing last-generation instruments. The PS4 version costs $59.99 as expected, while the Xbox One version costs $79.99.
The extra $20 cost exists because the stand-alone Xbox One game comes bundled with a peripheral: the Legacy Game Controller Adapter, which enables support for "most" Xbox 360 wireless instruments. Harmonix has put together an instrument compatibility chart that it will update over time (see below).
The adapter is necessary because for the Xbox One, Microsoft changed the wireless connection between the console and its controllers, making it impossible for the Xbox One to offer built-in support for Xbox 360 peripherals. (The Xbox 360 natively supported wireless Rock Band instruments, unlike the PS3, which required USB dongles for them.)
"We worked closely with Microsoft to let players use their legacy Rock Band and third party guitars and drums on the Xbox One, as we all understood the value there," said Harmonix in a statement to Polygon. A Harmonix spokesperson confirmed the company will be selling the Legacy Game Controller Adapter separately, but couldn't yet confirm the price of the stand-alone adapter.
Rock Band 4 players on Xbox One will need the Legacy Game Controller Adapter to use any last-generation wireless instruments. Asked about compatibility with wired Xbox 360 peripherals, the Harmonix representative told Polygon, "We don't currently support wired USB instruments." Note the use of the word "instruments" — this applies only to guitars and drums. Rock Band microphones have always been wired USB peripherals, and old ones are supported on all platforms, no adapter necessary.
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There's no denying that PlayStation customers get the better deal here. Although they'll need to dig out all the USB dongles for their PS3 wireless instruments if they want to use them with Rock Band 4, they'll be able to do so without the $20 adapter that's required on Xbox One. And the PS4 version of the game supports legacy wired instruments as well as wireless peripherals, the Harmonix rep confirmed to Polygon. (This even applies to the guitars and drums from the PlayStation 2 version of the original Rock Band, according to Harmonix's compatibility chart.)
Customers who are looking to play Rock Band 4with current-generation instruments — either because they don't have old ones, want new ones or are migrating to a new console family — will have to pay a pretty penny for them. The game bundled with a single wireless guitar costs $129.99, while the full-band set (game, guitar, drum set, microphone) costs $249.99.
Rock Band 4 launches Oct. 6 on PS4 and Xbox One. Harmonix also announced 10 new songs from the game's soundtrack today, including Soundgarden's "Superunknown" and Cake's "Short Skirt/Long Jacket." You can check out the full list below, and see a few of the songs in action in the video above. We've also embedded the current compatibility chart below; the latest version will be available in the Harmonix forums.

• .38 Special - "Caught Up In You"
• Arctic Monkeys - "Arabella"
• The Both - "Milwaukee"
• Cake - "Short Skirt/Long Jacket"
• Little Big Town - "Little White Church"
• Lucius - "Turn It Around"
• The Mighty Mighty Bosstones - "The Impression That I Get"
• The Protomen - "Light Up The Night"
• Soundgarden - "Superunknown"
• Tijuana Sweetheart - "Pistol Whipped"

Source: Rock Band Youtube, Ploygon