The sixteen metal strings in the Roosebeck Lyre Harp set provide a very classical sound. The recommended tuning as outlined below specifies the octave as well as the note. This tuning is in the key of D and spans two full octaves plus one. The strings are steel with the lowest four being nickel wound.Tuning and String Gauges 1:E5.0100.25Steel2:D5.0100.25Steel3:C#5.0100.25Steel4:B4.0120.30Steel5:A4.0120.30Steel6:G4.0120.30Steel7:F#4.0150.38Steel8:E4.0150.38Steel9:D4.0150.38Steel10:C#4.0180.46Steel11:B3.0180.46Steel12:A3.0180.46Steel13:G3.024w0.61 Nickel 14:F#3.024w0.61Nickel15:E3.024w0.61Nickel16:D3.028w0.71Nickel