The 49ers lost in last season’s NFC title game, but running back Frank Gore, left, and Coach Jim Harbaugh have taken that next step to reach the Super Bowl this year. (Kevin C. Cox/GETTY IMAGES)

At one end of the Georgia Dome, there was music. San Francisco 49ers players celebrated, although quarterback Colin Kaepernick was nowhere in sight. His locker was the picture of quiet in a scene of pandemonium. It was unlikely, but then again, the same could be said of Kaepernick’s rise.

“He came here midseason,” 49ers tight end Vernon Davis said of his quarterback, “and just turned everything around.”

Maybe a hundred yards in another direction, there was silence. Another tight end, Tony Gonzalez, sat in his pads and said nothing. Players consoled each other and said goodbye. Team officials loaded playbooks into a trunk, one they would soon close like a casket.

The Atlanta Falcons had lost, 28-24, in their home stadium. They weren’t NFC champions. They wouldn’t be going to the Super Bowl. Atlanta’s quarterback, Matt Ryan, also was elsewhere.

Sunday’s NFC title game showed the subtleties of a complicated game. Kaepernick continued his unlikely ascent and Ryan added further evidence that he seems unable to win big contests. This was a game that typified Kaepernick’s season — mesmerizing, unpredictable, breakneck — and Ryan’s career: such talent, but something was missing on the biggest of stages.

Ryan was almost flawless in the first half. He threw for 271 yards and three touchdowns in leading his team to a 24-14 halftime lead. Ryan and wide receiver Julio Jones looked unstoppable; if Ryan threw a pass, no matter the distance or traffic, Jones seemed able to haul it in.

At halftime, 49ers Coach Jim Harbaugh addressed his team. So did Davis. Kaepernick listened. There were no rousing words from the 25-year-old, a second-year quarterback making just his ninth career start. Kaepernick, of course, was named San Francisco’s starter in Week 11, only because his predecessor, Alex Smith, suffered a concussion.

Harbaugh then made a decision that was questioned even in his own locker room: Even after Smith was healthy, Kaepernick would be his starting quarterback.

“We respected the decision that he made,” Davis said of his coach. “A lot of guys weren’t happy about it, but we had to respect it.”

San Francisco tackle Joe Staley said players accepted Harbaugh’s move and, because this is how it is for an NFL team, believed in Kaepernick.

“We didn’t have any choice,” Staley said.

Kaepernick has mostly downplayed the move.

“I’m just thankful he made that decision,” he said.

In the second half, Kaepernick was calm despite the deficit and the noise inside the Georgia Dome. He led his team’s offense, firing perfect throws and, though he rushed only twice, made plays when he needed to. Kaepernick rediscovered Davis and handed off to Frank Gore. Kaepernick is highly skilled, but perhaps his greatest talents are to keep defenses off balance and his teammates from losing their nerve.

“Nobody was panicking,” Staley said. “Nobody was fretting.”

Davis put it another way.

“All that I remember,” he said, “was saying to myself: ‘We’ve got this.’ ”

Ryan, the No. 3 overall draft pick in 2008, has reached the playoffs four times. Falcons General Manager Thomas Dimitroff has surrounded Ryan with superstars, even gambling in 2011 when he traded Cleveland five draft choices to move up 21 spots and select Jones.

Ryan has mostly led a charmed career, his only shortcoming being that, entering this postseason, he was winless in the playoffs. Atlanta barely beat Seattle last week, but something always seems to happen to this poised, talented quarterback when his team needs him most: in four career playoff games entering Sunday, Ryan had thrown six interceptions.

Against the 49ers, Ryan had another pass intercepted when wide receiver Roddy White appeared to slip, and Ryan later mishandled a shotgun snap, allowing San Francisco’s Aldon Smith to fall on the loose ball.

After Kaepernick led his team to the go-ahead touchdown with a little more than eight minutes remaining, Ryan had one final chance. One opportunity to show that experience beats even a football phenomenon; to prove that he has overcome his biggest weakness.

Instead, 49ers linebacker NaVorro Bowman deflected a short pass on fourth down, and Ryan was left to walk back to his sideline with about a minute to play, while another team celebrated on the Atlanta turf. Bowman said the 49ers changed nothing about their defense to slow Ryan and keep the Falcons scoreless in the second half. Instead, defenders just allowed Ryan to make mistakes.

Yes, another loss for Ryan, who is now 1-4 in the postseason, and another win for Kaepernick, who is now one win from being a Super Bowl champion in his first season as a starter.

Ryan and Kaepernick eventually did make their way to their lockers, different as the scene was for each. Ryan, who suffered a shoulder injury in the fourth quarter but later said he was fine, dressed and talked about disappointment.

“We just fell short,” he said.

Kaepernick slapped on a white cap and pulled a T-shirt over his shoulder pads. Both had the word “CHAMPIONS” printed in large type.

Ryan was morose. Kaepernick elated. This is life in the NFL playoffs, when vast differences in journeys and results are sometimes difficult to explain.

“Just excited,” Kaepernick said, “to keep going.”