The Signs As Instruments:

Aries: Guitar, Acoustic or Electric

Taurus: Drums

Gemini: Marimba

Cancer: Viola

Leo: Vocals

Virgo: Cello

Libra: Bass, Guitar or Classic

Scorpio: Violin

Sagittarius: Tambourine 

Capricorn: Piano

Aquarius: Pan Flute

Pisces: Cajole