: Tighten or loosen the string until the pulsing slows down and eventually disappears, meaning your instrument matches the pitch perfectly.

: If you need this on the go, apps like gStrings (Android) or Pano Tuner (iOS) provide a reference tone feature that mimics a physical tuning fork. Guide to Using the Reference Tone

: When tuning your instrument (like a guitar or violin), play your "A" string alongside the recorded sound. If you hear a "wah-wah-wah" pulsing sound (beats), your instrument is out of tune.