Q. If someone bought a new expensive great guitar, he uses for playing during simches, does he recite Shecheyanu or Hatov Vehameitiv?

A. On question 3759 regarding reciting Shecheyanu bracha when a new Sefer Torah is donated and introduced to the Shul, we wrote; “Horav Shlomo Miller’s Shlit’a opinion is that it may be proper to recite the blessing of Hatov Vehametiv in such a case, since many will benefit from it.”

Similarly on question 103 on buying a car we wrote: “Horav Shlomo Miller’s Shlit”a opinion is that since this car will presumably be used by other members of the family too, the correct brocho to be recited would be Hatov Vehameitiv, (as more than the buyer will benefit from it) and not Shechecheyanu, (see Igrois Moishe O. H. 3: 80)
However, in our case the Rov maintains that the brocho should be Shechecheyanu,

Rabbi A. Bartfeld as revised by, Horav Dovid Pam, Horav Aharon Miller, Horav Chanoch Ehrentreu and Horav Kalman Ochs Shlit’a