Chris Brown celebrates his 27th birthday today by releasing new single 'Grass Ain’t Greener.' The melodic R&B mid-tempo, which lacks growth, addresses his break-up with Karrueche Tran (yawn.) He needs to go away for a while, come back at 30 and get re-inspired. 'Grass' is slated to appear on his upcoming eighth solo album 'Heartbreak on a Full Moon,' due later this year.