5 Seconds of Summer's Luke Hemmings showed off his incredible voice as he appeared on The Tonight Show: At Home Edition on Thursday night. Ahead of the release of the band's Calm album, the 23-year-old singer performed an acoustic version of their latest single "Old Me." With only a guitar backing him up, Hemmings completely blew us away with his vocals, especially those high notes! Of course, one of the cutest parts was how he included his own sound effects in the beginning with a previous clip of Jimmy Fallon saying "Please welcome tonight's musical guest, 5 Seconds of Summer," before cracking a smile at the camera. Fast-forward to the 23:58 mark to watch his full performance.