| 1 | SELECT encoder | Controls various aspects of the S4, including tempo, device power, and general navigation through pushing or rotating. |
| 2 | Built-in microphone | – |
| 3 | [PROJECT] button | Access saving, loading and create new projects. Learn more. |
| 4 | [CONFIG] button | Access configuration options of the S4. |
| 5 | LCD display | – |
| 6 | [MOD] button | Various modulation-related functions. Learn more (broken reference). |
| 7 | Triangle [ACTION] button | Context-dependent buttons that change function based on what's on the screen. |
| 8 | Square [ACTION] button | – |
| 9 | Hexagon [ACTION] button | – |
| 10 | Circle [ACTION] button | – |
| 11 | PARAMETER encoders | Adjust parameters and set values by pushing or rotating the endless encoders. |
| 12 | [DEVICE] buttons | Device slot navigation: [MATERIAL], [GRANULAR], [FILTER], [COLOR], [SPACE]. Learn more (broken reference). |
| 13 | [PLAY/STOP] button | Start and stop playback. |
| 14 | [TRACK] button | Tracks navigation. Learn more: ../../track-overview/ |
| 15 | [SCENE] button | Open the SCENE page. Learn more: ../../perform-and-scene/scene-overview/ |
| 16 | [MIX] button | Four track mixer and master output. Learn more: ../../miscellaneous/mix-view |
| 17 | [COPY] button | Copy and paste current state. Learn more: ../../miscellaneous/copying-and-pasting |
| 18 | [CLEAR] button | Hold with another function to clear and delete. Learn more: ../../miscellaneous/clearing-and-resetting |
| 19 | [CTRL] button | Hold to access secondary functions. |
| 20 | [PERFORM] button | Open the PERFORM page. Learn more (broken reference). |
| 21 | [TEMP] button | Activates temporary control functionality. Learn more: ../../miscellaneous/temporary-control |