Apple Music Sing karaoke mode does not work on many devices. Macworld suggests that this is due to the high technical requirements.
Sing only works on devices with an A13 processor or newer and 4 GB of RAM or more. For this reason, karaoke mode is not available on the 2nd generation iPhone SE. Although it contains the A13 chip, it only has 3 GB of RAM.
The CPU requirement is probably due to the neural engine, which is much more powerful in A13 than in A11 and A12.
Why does Apple’s latest music feature have such high system requirements?
Apple Music Sing won’t even work on last year’s Apple TV 4K.
www.macworld.com
Source: Iphones RU
