1993 Cavalier cuts off when driving HELP!

I have a 93 cavalier 5 speed stick 2.2 coupe,140400 miles. It cuts off while toolin' down the road! I just depress the clutch let it idle down crank it back up(starts right away) and on we go..what the heck is that all about? I was told they go through alternators like candy, how is THAT to be avoided? Don't say 'by parking it' as I like my little car that gets 40mpg vs Dodge ram conversion vans' 9mpg! I like this little car and was suprised at the speed and power off the line. I used to street race in my highschool days about 100 years ago. Muscle cars etc. I was impressed the first time I got on this little car that I could squawk the tires in the first three gears! This little thing tried to scoot out from under me! I just thought the Z24's were capable of this, are all Cavs like this? I really want to know more about my car. I am sure it is completely stock at this point and will no doubt keep it that way.HEY can anyone tell me what that little tune means when I turn off the car? Not the 'ding ding you left something on" one. the other one. It sounds four notes twice then is silent.