I seems that most prefer an external hard drive for storing music. Is this a preferance over just adding more memory to your Apple Computer?
You wouldn't be adding "memory", but you'd need to add more storage space (a larger hard drive). There is no room in a laptop (nor a MacMini) to add an additional drive. If you are using a tower, sure you can add a larger additional hard drive internal to the tower. Folks use external drives because they are portable and can be moved from one computer to another, are relatively cheap, and do not interfere with the operating system running smoothly by clogging up that drive with additional information. With the current operating systems, at least where Mac OSX is concerned, it is better to give the boot drive plenty of free space for the operating system to run (I try to keep at least 1/3 of my disc empty). You have a faster happier computer that way. A moderate CD collection can easily fill up a hard drive in lossless or especially uncompressed formats (300mb/CD in Apple Lossless and 600mb/CD in WAV). I can take my entire music library to share listening while visiting a friend, or while traveling, simply by packing my external hard drive which is about the size of a small hardcover book. If I stored the music in an internal drive in my tower computer I would not have that option unless I wanted to tote my entire computer along. My collection currently fills a 300GB external drive in a mix of WAV and Apple Lossless files.
Marco