This achievement requires several upgrades from the General Store, including the first $5,000 upgrade to the General Store itself. Once you have the train and the first General Store Upgrade, there should be a new purchase option that looks like the control panel of the train with a price tag of $500. This is the first upgrade for the sound system. After you leave the town area and return, upgrade level 2 should be available for $5,000. Purchasing upgrade level #2 unlocks the achievement.