WRONG FREQ GUARDED AS FREQ CHANGE MISSED.

Narrative

WX AT TIME OF DEP: FOG LOW VISIBILITY; 32 DEG F; LOW CEILING; SNOWING. RAMPS AND TAXIWAYS: COVERED WITH ICE AND SNOW. ACFT WAS DE-ICED AFTER PUSHBACK; BEFORE ENG START. AFTER ENG START; BOTH GATE HOLD AND GND CTL FREQ WERE CONGESTED AND CONFUSED. ACFT AND CTLRS CUT EACH OTHER OUT. WE TAXIED OUT OF GATE PLANNING ON 29R. 29R BECAME CLOSED FOR PLOWING. WE WENT TO 29L INSTEAD; HOWEVER THE FO LEFT THE TWR FREQ FOR 29R IN THE #1 COM. THE TWR CTLR BROADCAST ON THE 29R FREQ FOR BOTH 29L AND 29R WHILE WE WERE IN LINE FOR DEP ON 29L. I WAS PREOCCUPIED WITH ADVERSE WX PROCS: I.E. SLIPPERY RAMP; ACFT CLRNCS; RUNNING UP ENGS EVERY 10 MINS TO CLR THEM; AND OF COURSE; UPPER WING ICE ON OUR MLG. I EVEN SENT THE FO BACK (WHILE THE BRAKES WERE SET) TO VISUALLY CHK THE WINGS FOR ICE WHEN WE WERE #2 FOR TKOF. WHEN WE WERE #1 HOLDING SHORT OF 29L; IT DAWNED ON THE FO AND ME THAT THE TWR CTLR WAS NOW ONLY GIVING INSTRUCTIONS FOR 29R. SHEEPISHLY; THE FO DIALED IN THE 29L FREQ AND CHKED IN. THE 29L CTLR ASKED IF WE HAD FREQ PROBLEMS. WE SAID YES; EMBARRASSED. THIS COULD HAVE BEEN AVOIDED IF THE 29R TWR CTLR HAD NEVER BROADCAST ON BOTH 29L OR R FREQS. THE SILENCE WOULD HAVE ALERTED US.