Rock Band 4 releases today, and several major outlets have a shortage of the game's Xbox One edition.

Reportedly, Amazon, Game, GameStop and ShopTo are all out of copies of the Xbox One version. Rock Band 4's physical version is the one unavailable, which offers a Legacy Game Controller Adapter, allowing you to play with your Xbox 360 instruments on the Xbox One.

Mad Catz Global PR Executive Alex Verrey addressed the situation, and reassured fans that they will be restocking retail shelves' starting today.

"We're thrilled at the reception both critically and commercially to Rock Band 4 and have been overwhelmed with demand since pre orders opened."

"For months now we have been saying again and again how important it was to pre-order if you wanted to receive hardware on day one. We did warn that demand would be high!"

"To reassure fans, the standalone version of the game on Xbox One (which comes with the Legacy Game Controller Adapter included) has absolutely NOT been delayed in any way. As promised, it is shipping today and those who pre ordered will start receiving it from today."

"Retail will also be stocking it from today, with the game on shelves nationwide, however, as stated earlier, demand is high. More stock will be arriving throughout October and I would like to stress that the quickest way to ensure delivery is to get an order in now via retailers such as Game, Amazon or indeed the Mad Catz website. We're deeply sorry if any fans are having difficulty purchasing today, we're doing everything we can to make sure more stock arrives very shortly."

Rock Band 4 is downloadable through the the Xbox One Games Store, but you will have to buy Xbox One-compatible instruments or the adapter by itself. On the other hand, PS3 instruments are supported on the PS4 without any additional hardware or software. That's why there is demand on Rock Band 4's physical version of the Xbox One specifically.