What are the differences between a baritone guitar and a 7-string guitar, and how do these differences affect their sound and playability?

A baritone guitar has a longer scale length and is tuned lower than a standard guitar, while a 7-string guitar has an extra string tuned lower than the standard 6 strings. The baritone guitar produces a deeper and richer sound due to its lower tuning, while the 7-string guitar offers extended range and versatility in playing different styles of music. The differences in scale length and tuning affect the playability by requiring different fingerings and techniques to accommodate the lower notes on the baritone guitar and the additional string on the 7-string guitar.