ABC became an aggressive competitor to NBC and CBS when, continuing NBC Blue's traditions of public service, it aired symphony performances conducted by Paul Whiteman, performances from the Metropolitan Opera, and jazz concerts aired as part of its broadcast of The Chamber Music Society of Lower Basin Street announced by Milton Cross. The network also became known for such suspenseful dramas as Sherlock Holmes, Gang Busters and Counterspy, as well as several mid-afternoon youth-oriented programs. However, ABC made a name for itself by utilizing the practice of counterprogramming, with which it often placed shows of its own against the offerings of NBC and CBS, adopting the use of the Magnetophon tape recorder, brought to the U.S. from Nazi Germany after its conquest, to pre-record its programming. With the help of the Magnetophon, ABC was able to provide its stars with greater freedom in terms of time, and also attract several big names, such as Bing Crosby at a time when NBC and CBS did not allow pre-taped shows.