Find any giver pitch on any giver instrument with the colorful Tuner that analyzes incoming audio and exactly shows you the main pitch.
Or you may start plotting the detected pitch an endless Pitch Roll and have fun drawing ups and downs with sound. Much more complex and information rich plot is produced by the Spectrograph that draws FFT frequency content of any incoming audio.
We can not only analyze, but produce different pitches with this web-site. There's a traditional Drone machine that will generate a rich in upper harmonics sound of any desired pitch and a fifth above it to generate a pleasant background for vocal practice and instrument tuning.
If you want to combine more simultaneous drone pitches - feel free to browse the Pitch table of all audible audio frequencies and beyond!