It's big and heavy. Even if you get one with a reduced fret count, it's still big and heavy. It has to be. If he's anything like I was at 8, it's going to be as tall as him and weigh half as much. Start him on the guitar, if you're looking for suggestions. Bass is easier, but there is less you can do with it end-game. How many kick ass licks can you think of for bass? The intro bass to Sweet Child Of Mine? Paradise City? Maxwell Murder bass solo? That's pretty much all that comes to mind, though I'm sure there's a lot more out there.

Hi I'm Steve from cooldiscountinstruments.com we sell a lot of basses for adults and kids so I think i can be helpful. A standard full size adult electric bass guitar is 47 inches long more or less. It can be longer or shorter depending on the design of the bass body and headstock but that is the most common length. It usually weighs in the neighborhood 11 pounds. It is difficult for anyone under the age of 12 to play a full size adult electric bass guitar, although there are exceptions. Alternatively there are 3/4 scale bass guitars which are shorter and lighter and could be played by 9 year old (as long as they are not small for their age). 8 years old seems a little young for a 3/4 bass, but you never know. http://cooldiscountinstruments.com/shop/Electric-Bass-Guitars-Small-Scale-Basses/c50_55/index.html Due to the laws of physics it is impossible to make a steel string bass shorter than a certain length. The strings would need to be so thick as to make it impractical to build. So, someone invented something called the Ashbory travel bass. http://cooldiscountinstruments.com/shop/advanced_search_result.php?keywords=ashbory&x=0&y=0&categories_id=&inc_subcat=1&manufacturers_id=&pfrom=&pto=&dfrom=&dto= It is very small and light and would be perfect for a younger player. It uses silicone strings instead of steel strings so that it can tune to the lower pitches at the proper tension without having to use super fat and impractical string gauges. they sound very deep and full, like a stand-up bass almost. An 8 year old (or younger) could certainly play this. hope this helps, Steve 2kool4skool Musical Instruments Carlsbad, CA

Electric guitars are smaller and lighter. Plus, a bass will likely bore an 8 yr old as he progresses. Get him into a 3/4 size electric guitar. I did a search on Musicians Friend, A good dot com, and here are the results. http://guitars.musiciansfriend.com/electric-guitars/travel-mini I would buy the "Squier by Fender Mini Strat Electric Guitar".

If the young lad wants to play a bass, get him one. No time like the present to get him started.