Aliovalent substitution of 1-2 % Mn and Ga for Ti has been carried out in the high-temperature ternary system (x)Bi(Zn0.5Zr0.5)O-3-y)BiScO3-(100-x-y)PbTiO3 near the morphotropic phase boundary, specifically 2.5BZZ-37.5BS-60PT in an attempt to reduce the loss tangent. Modifications of this particular composition were chosen due its high-Curie temperature of 420 A degrees C and excellent piezoelectric coefficient of 520 pm/V. Dielectric, piezoelectric, and electromechanical properties were characterized as a function of temperature, frequency, and electric field for all compositions. Small concentrations of Mn and Ga were shown to increase both the electrical and mechanical quality factors, with a Q (m) and Q (e) of 300 and 150, respectively, from room temperature up to 300 A degrees C for Mn-doped compositions.