VAIL - While some of the world's foremost adventure athletes tackle the mountains and rivers of Vail during the 11th annual Teva Mountain Games, some equally prominent musical artists will take to the main stage for a pair of free concerts when the Mountains of Music series rocks Vail Village May 31 and June 2.Both free shows will be on the main Teva Mountain Games stage at Checkpoint Charlie in Vail Village and both will get underway at 7 p.m. The May 31 performance with Williams will be held in conjunction with the event's opening ceremonies.Williams first appeared on the music scene in the early '90s and has defined the independent artist. Keller built his reputation initially with engaging live performances, no two of which are ever alike. Most of his career is spent performing as a one-man band. Williams' solo live shows and his ability to improvise his quirky tunes have become the stuff of legend. Williams will bring an exciting and unpredictable live performance to the streets of Vail.The Expendables are down-to-earth guys from a little surf town called Santa Cruz. The band's classic summertime sound blends reggae, '80s punk rock and ska, with songs that have made heads turn and floors shake for 15 years. The California surf-rockers have toured with big names in the genre including 311, Pepper, Fishbone, G. Love & Special Sauce and Slightly Stoopid.Prior to the Williams show, competitors from around the world will gather in Vail Village to kick off the Teva Mountain Games at the official opening ceremonies. Athletes from more than 25 countries will create an international parade up Gore Creek Drive to the Checkpoint Charlie stage, culminating in welcome speeches and an athlete oath by the IFSC World Cup Bouldering competitors. For more information, visit www.tevamountaingames.com. Follow Teva Mountain Games on Facebook and @TevaMtnGames on Twitter.