Trademark distinctiveness both concepts, see Apple Corps and its disputes with Apple, Inc. If a court rules that a trademark has become "generic" through common use (such that the mark no longer performs the essential trademark function and the average consumer no longer considers that exclusive rights attach to it), the corresponding registration may also be ruled invalid. For example, the Bayer company's trademark "Aspirin" has been ruled generic in the United States, so other companies may use that name for acetylsalicylic acid as well (although it is still a trademark in Canada). Xerox for photocopiers and Band-Aid for adhesive bandages are
Willow flute tempered scale. Modern willow flutes are typically made of plastic (PVC tubing is often used), but the original willow flutes were made from sections of bark cut from green willow branches. Willow flutes could only be made this way during the spring, and became unplayable when the bark dried out. Noted modern willow flute artists include the group Hedningarna and Anders Norudde of Sweden. Other Scandinavian groups that use the Seljefløyte in traditional arrangements include Eivind Groven, Steinar Ofsdal, Groupa and Bask. There is also a Karelian variant of the willow flute that is made in Finnish Karelia and the