Royal Knights
I believe that this 45 was the only release by this set of Royal Knights and going by the addresses on the two singles it must have been cut somewhere in Pennsylvania in the 60s. The Donna release (the second one?) gives the name of the excellent lead singer as B W Williams and he does a really fine job on the lyrics of 
Have You Heard, full of emotion and gospel touches. The backing is about as simple as you can get - just a bare rhythm section - but the guitarist plays some lovely arpeggios and the girls in the background add some welcome tonal colour. A strong track.
Note ~ This group isn't the same as the Texas Chicano one or the combo who also cut as the New Yorkers who you can find here.