Morse code is more sensitive to poor signal conditions.
MFSB -LRB- according to the `` clean '' interpretation , Mother Father Sister Brother -RRB- was a pool of more than thirty studio musicians based at Philadelphia 's famed Sigma Sound Studios .. Philadelphia. Philadelphia. studio musicians. studio musicians. Sigma Sound Studios. Sigma Sound Studios. They worked closely with the production team of Gamble and Huff and producer / arranger Thom Bell , and backed up such groups as Harold Melvin & the Blue Notes , the O'Jays , the Stylistics , the Spinners , Wilson Pickett , and Billy Paul .. Harold Melvin & the Blue Notes. Harold Melvin & the Blue Notes. Thom Bell. Thom Bell. Gamble and Huff. Gamble and Huff. the Stylistics. the Stylistics. the Spinners. The Spinners ( U.S. band ). Wilson Pickett. Wilson Pickett. Billy Paul. Billy Paul. In 1972 , MFSB began recording as a named act for the Philadelphia International label .. Philadelphia. Philadelphia. Philadelphia International. Philadelphia International. `` TSOP -LRB- The Sound of Philadelphia -RRB- '' also known as the Soul Train theme was their first and most successful single .. Philadelphia. Philadelphia. Soul. Soul music. Soul Train. Soul Train. Released in March 1974 , it peaked at number one on the US Billboard pop and R&B charts .. R&B. Hot R&B / Hip-Hop Songs. Billboard. Billboard ( magazine ). pop. Billboard Hot 100. charts. record chart. `` TSOP '' was influential in establishing the disco sound .. disco. disco. The track sold over one million copies , and was awarded a gold disc by the RIAA in April 1974 .. gold disc. music recording sales certification. RIAA. RIAA