             expect(pitch).toNot(beNil())
             expect(pitch.note).to(equal(Note.E))
             expect(pitch.octave).to(equal(7))
-            expect(pitch.frequency).to(equal(2637.02))
+            expect(pitch.frequency) ≈ (2637.02, 0.01)
           }
 
           it("creates F3") {

            expect(pitch).toNot(beNil())
            expect(pitch.note).to(equal(Note.CSharp))
            expect(pitch.octave).to(equal(6))
            expect(pitch.frequency).to(equal(1108.73))
          }

          it("creates D5") {

            expect(pitch).toNot(beNil())
            expect(pitch.note).to(equal(Note.GSharp))
            expect(pitch.octave).to(equal(3))
            expect(pitch.frequency) ≈ (207.652, 0.01)
          }

          it("creates A4") {
