It has been quite warm here in Idaho, so museums have been our better bet. Before leaving Idaho Falls, we spent a good part of Monday at the Museum of Idaho. It has an interesting temporary exhibit with the title "Guitar: The Instrument that Rocked the World". Considering that 3 million guitars are sold yearly, more than all the other instruments combined, it would seem that there would be a lot of interest in this exhibit of everything having to do guitars. It was a busy place when we there. On display is an 8-neck guitar built by the National Guitar Museum, which has been played by 8 musicians- it is called the Rock Ock. Also in this exhibit is the world's largest playable guitar. It is 43.5 feet long and 16 feet wide. It has been certified by Guiness Book of World Records. A fun part of this exhibit features hands-on experiences with the science of sound and the design and engineering of the guitar.