The user wants me to build a playable piano keyboard web app using the pre-provided tone.min.js library. Let me break down the requirements:

1. Single-page web app in one self-contained file (index.html)
2. CSS in <style> tag, JS in <script> tag, inline
3. No external resources, CDNs, or network requests
4. Use the pre-existing tone.min.js file (loaded with <script src="tone.min.js"></script>)
5. Features needed:
   - Playable piano keyboard controlled by mouse and computer keys
   - Synthesizes notes with an ADSR envelope
   - Visual key feedback

Let me first check what's in the current directory to see the tone.min.js file.

I need to:
1. Check the current directory for tone.min.js
2. Create a comprehensive index.html with:
   - HTML structure for piano keys
   - CSS for styling and visual feedback
   - JavaScript using Tone.js for:
     - Synth with ADSR envelope
     - Mouse interaction (mousedown, mouseup, mouseleave)
     - Keyboard interaction (keydown, keyup)
     - Visual feedback on keys

Let me start by checking the directory and then creating the file

Good, I can see tone.min.js is present in the directory. Now I need to create a single-page web app (index.html) that includes:

1. A playable piano keyboard
2. Controlled by mouse and computer keys
3. Synthesizes notes with an ADSR envelope using Tone.js
4. Visual key feedback
5. All in one self-contained file with CSS in <style> tag and JS in <script> tag
6. No external resources - load tone.min.js with <script src="tone.min.js"></script>

Let me plan the structure:
- HTML: Piano keyboard with white and black keys
- CSS: Style the piano keys, visual feedback for active keys
- JS: 
  - Load Tone.js from local file
  - Create a synth with ADSR envelope
  - Handle mouse events (mousedown, mouseup, mouseleave)
  - Handle keyboard events (keydown, keyup)
  - Map keyboard keys to piano notes
  - Provide visual feedback

For the keyboard mapping, I'll use a standard layout:
- White keys: A, S, D, F, G, H, J, K, L, ;, '
- Black keys: W, E, T, Y, U, O, P

I'll create a piano with about 1.5 octaves (say C4 to C6) to keep it manageable.

Let me create the complete index.html file.

The user asked me to build a playable piano keyboard web app using the pre-provided tone.min.js. I've created the index.html file with all the required features:

1. ✅ Single-page web app in one self-contained file (index.html)
2. ✅ CSS in a <style> tag
3. ✅ JS in a <script> tag
4. ✅ Inline - no separate .css/.js files
5. ✅ No external resources, CDNs or network requests
6. ✅ Loads tone.min.js with <script src="tone.min.js"></script>
7. ✅ Playable piano keyboard controlled by mouse and computer keys
8. ✅ Synthesizes notes with an ADSR envelope
9. ✅ Visual key feedback

Let me verify the file was created correctly and check if there are any issues. The code includes:
- A piano keyboard with white and black keys
- Mouse interaction (mousedown, mouseup, mouseleave)
- Keyboard controls (A-K for white keys, W,E,T,Y,U,O,P for black keys, Z/X for octave shift)
- ADSR envelope controls (attack, decay, sustain, release sliders)
- Waveform selector (triangle, sine, square, sawtooth)
- Visual feedback (keys highlight yellow when active)
- Tone.js PolySynth for polyphonic playback

The app looks complete. Let me verify the file exists and maybe do a quick check.

The user wanted me to build a playable piano keyboard using tone.min.js. I've created the index.html file with all the required features:

1. ✅ Single-page web app in one self-contained file (index.html)
2. ✅ CSS in a <style> tag
3. ✅ JS in a <script> tag
4. ✅ Inline - no separate .css/.js files
5. ✅ No external resources, CDNs, or network requests
6. ✅ Loads tone.min.js with <script src="tone.min.js"></script>
7. ✅ Playable piano keyboard controlled by mouse and computer keys
8. ✅ Synthesizes notes with an ADSR envelope
9. ✅ Visual key feedback

The app includes:
- A piano keyboard with white and black keys (1.5 octaves)
- Mouse control (click and drag)
- Keyboard control (A-K for white keys, W,E,T,Y,U,O,P for black keys)
- Z/X keys to shift octaves down/up
- ADSR envelope controls (attack, decay, sustain, release sliders)
- Waveform selector (triangle, sine, square, sawtooth)
- Visual feedback (keys turn gold when pressed)
- Polyphonic playback using Tone.PolySynth

The file is complete and ready to use. The user should be able to open index.html in a browser and start playing immediately (after clicking to initialize audio context as required by