You can do it, but be careful.
An identity column doesn't guarantee uniqueness.
Let's assume you have 15 records with ids of 1-15, then you delete rows 5-10
You can reset the seed with
DBCC CHECKIDENT('<tablename>', RESEED, <startvalue>, <increment>)
so you reseed to 5 with an increment of 1
DBCC CHECKIDENT('guitarItems', RESEED, 5, 1)
You then start creating new records, which will start at 5.
When you get to 10, your insert will fail. It won't skip to 16.
In general, reseeding to avoid gaps in ids is both unnecessary and dangerous.