If you need a smile, just take a look at these 9-month-old twins, Reece and Levi, who have totally captured our hearts with their rendition of Johnny Cash's 'Folsom Prison Blues.' While their harmonies may be in the form of squealing -- they're too young to actually sing the lyrics -- these two really set the bar high.

The video itself is a few years old, but the adorableness factor these sweet babies bring will never ever grow old. The twins are found in their new Jolly Jumper contraptions -- an exercise toy for any baby in the pre-walking stage. As Cash sings the somber song in the background, the babies bring a stark contrast to the dark lyrics, giggling and screaming as they jump higher and higher and higher. At one point, one of the twins stops to take a breather, but as soon as he sees his brother's legs springing up and down like a frog, he hops right back in -- literally.

God bless the inventor of the Jolly Jumper; it's never-ending entertainment for kids and adults alike!