About a third of violin players acknowledge leaving their instrument vulnerable to theft, a large portion of them in cars. Which is a very, very bad idea.

In most major cities in the developed world, it’s a pretty common truism that leaving something on a car seat is an invitation to thieves. Something so worthless as an empty paper bag might be tempting enough for a smash-and-grab, just on the chance it contains a wallet or smartphone.

The cavalier among us might joke, “Heck,…