Abstract: A metal musical string having a plastic or polymer material covering an end of the string opposite to a ball end of the string is contained in a flexible enclosure or pouch. In a coiled configuration, the ends of the string are twisted around convolutions of the coil to maintain the coil configuration. Different colors of polymer material cover ends of respective different music strings to identify the strings contained in the single pouch. The polymer material is either thin to allow insertion through holes or slots of musical instruments or removable. The flexible enclosure is a sealed gas impervious pouch filled with a non-corrosive gas such as nitrogen, carbon dioxide, argon, helium, etc.

Abstract: An electronic tuning device has selectable width tuning ranges wherein selected pairs of the LEDs in a single row of LED's are activated, such as being turned on, blinked or flashed, so that the spacing between each activated pair of LEDs indicates the width of the tuning range during a range indicating mode. The sensing of a fundamental frequency of an input tone causes the operation of a corresponding LED in the row of LEDs to indicate the nearest note along with in-tune and out-of-tune conditions.

Abstract: An electronic tuning device includes a display with a single row of LED's corresponding to musical notes wherein the sensing of a fundamental frequency of an input tone causes the operation of the corresponding LED to indicate the nearest note. Additionally the LED is operated in manner, such as blinking proportionally to the variation from the note and/or producing different colors, such as green, red and amber, to indicate in-tune and out-of-tune conditions. A double back adhesive rubber pad can be used to removably mount the tuner on an instrument, so that the device can simply pulled off the musical instrument to make it ready for its next use. The rubber pad serves to attenuate high frequency mechanical vibrations of the musical instruments thus improving the accuracy and versatility of the unit. In one embodiment, the display is mounted externally on the musical instrument while the tone sensing circuitry is mounted inside the musical instrument such within the sound box of an existing guitar.

Abstract: Audio signals are digitized and an FFT is conducted on samples of the digitized signals to produce corresponding frequency spectrums. These spectrums are analyzed, such as by determining one or more peak frequency magnitudes which are 33 dB greater than harmonics or subharmonics of the frequency in a plurality of several successive spectrums, to detect resonating feedback frequencies. The offending frequency is then filtered in the time domain, either in the digitized form or analog form, to eliminate the feedback.

Abstract: An apparatus which clampingly engages the neck and the strings and fingerboard of a stringed instrument for selectively adjusting the pitch of the strings. The apparatus includes positioning guides for aligning the apparatus with respect to the frets which are disposed along the fingerboard and a pair of relatively thin, resilient string-engaging members which reduce undesirable string vibration and maintain proper string contact with the frets.