from qiskit import QuantumCircuit, execute, Aer

def quantum_melody(n_notes, n_pitches=12):
    """Generate melody via quantum measurement."""
    qc = QuantumCircuit(4, 4)
    qc.h(range(4))  # Superposition
    qc.measure(range(4), range(4))
    
    backend = Aer.get_backend('qasm_simulator')
    result = execute(qc, backend, shots=n_notes).result()
    
    melody = []
    for bitstring, count in result.get_counts().items():
        pitch = int(bitstring, 2) % n_pitches
        melody.extend([pitch] * count)
    
    return melody

def quantum_walk_melody(graph, steps):
    """Melody from quantum walk on graph."""
    from discopy.quantum import qubit, H, CNOT
    
    # Initialize walker in superposition
    walker = uniform_superposition(len(graph.nodes))
    
    for _ in range(steps):
        # Coin flip
        walker = apply_coin(walker)
        # Shift
        walker = apply_shift(walker, graph)
    
    # Measure to get note sequence
    return measure_melody(walker)

def find_chord(target_quality='major'):
    """Use Grover to find chord voicing."""
    # Oracle marks good voicings
    oracle = chord_quality_oracle(target_quality)
    
    # Grover iterations
    circuit = grover_circuit(oracle, n_qubits=12)
    
    # Measure result
    return measure_chord(circuit)

  Quantum Guitar          Grand Piano
       │                      │
    ┌──┴──┐                ┌──┴──┐
    │  X  │                │  Z  │
    └──┬──┘                └──┬──┘
       │                      │
       └──────────────────────┘
              Bell pair
              
  Measurement collapses entanglement
  → Correlated musical phrases

from discopy import Ty, Box, Diagram
from discopy.quantum import qubit, Ket, Bra, H, CX

# Musical types
note = Ty('note')
chord = Ty('chord')

# Quantum composition as diagram
def compose_phrase():
    # Prepare Bell state
    bell = Ket(0, 0) >> (H @ Id(1)) >> CX
    
    # Map to musical space
    to_music = Box('sonify', qubit @ qubit, note @ note)
    
    return bell >> to_music

quantum_music_performance:
  setup:
    - Actias on dedicated laptop
    - MIDI routing configured
    - Bloch sphere projection
  
  soundcheck:
    - Test foot controllers
    - Verify measurement response
    - Classical/quantum blend levels
  
  performance:
    - Smooth classical→quantum transitions
    - Real-time qubit manipulation
    - Measured moments for phrase endings

quantum-music (○) + SDF.Ch1 (+) + [balancer] (−) = 0