If you're a gigging musician, a backup guitar is essential in case your main guitar breaks or gets damaged. This will ensure that you can still perform even if your primary instrument fails.
When You Want a Different Sound
Different guitars produce different sounds, so if you're looking to expand your sonic palette, getting a second guitar with a different sound from your main instrument can be a great option. This will give you more versatility in your playing and allow you to experiment with different genres.
When You're Ready to Upgrade
If you've been playing guitar for a while and have outgrown your beginner instrument, upgrading to a better quality guitar can make a significant improvement in your playing. A better guitar will typically have better construction, materials, and sound quality, which can lead to a more enjoyable playing experience.
When You Simply Want Another Guitar
Of course, you don't need a practical reason to buy a second guitar. If you simply love guitars and want to add another one to your collection, there's no harm in doing so. Playing music is a hobby that should be enjoyed, and owning multiple guitars can make it even more fun.