Many thanks to SRAA contributor, Dan Greenall, who shares the following recording and notes:

Broadcaster: Voice of Nigeria, Nigerian Broadcasting Corporation 1971

Frequency: 7.275 MHz

Reception location: Ancaster, Ontario, Canada

Receiver and antenna: Hallicrafters S-52 using a longwire antenna

Notes: Here is a recording of the distinctive rapid drum beat interval signal used by the Voice of Nigeria in Lagos on shortwave, made sometime in 1971. A voice announcement follows, as they begin a program in the French language. In the second recording, you will hear their interval signal, anthem, and sign on in English. This recording was made circa 1971 on 7275 kHz.