<s>[INST] A local tavern would like to place 3 machines, from a collection of 4, in a row along the bar. Some guests seated at the bar may become annoyed if a music machine and a karaoke machine are placed beside each other because their noise levels may be distracting. How many arrangements of the 3 machines can be made along the bar which avoid placing a music and a karaoke machine beside each other?[/INST]