The rookie hit town a week after Lollapalooza did.
That music festival in Grant Park is filled with people looking for the next big thing. They want to see a new band early, to find out whether the buzz is deserved amid a throng of the curious.
And they want bragging rights. They want to get there first.
Javier Baez is a really exciting new band. He swings as hard as any young punk guitarist thrashes. Time will tell if he can keep it up, and whether he will add the nuance needed to be a more complete hitter. Maybe that guitar player has a decade of mature songs in him he doesn't even know about yet.
I fear for Baez's oblique muscles every time his bat crosses the plate. Healthy longevity with that violence of motion is difficult to conceive. But there is precedent.
You've heard the comps by now about Gary Sheffield. My colleague Barry Rozner sees some George Bell. Maybe like me you've also picked up some Vladimir Guerrero.
Baez thrashes at the ball, in or out of the strike zone. If Baez is going to be a star, he will need to approach the contact rate of Guerrero. Even though he walked more than 80 times just once in a season, Vlad had a lifetime OBP of .379. There were six seasons with an OBP over .390.
It would be a dream to find the plate discipline of Sheffield. That man struck out more than 70 times in just five of his 22 seasons, while piling up 1475 walks.
Is Bell's career an acceptable goal for Baez with this kind of hype? Bell had 265 home runs and 1002 RBI in a 12-year run, with just two seasons of 30 or more homers. His body was done at 33.
But defining Baez's future isn't really the point. He's the phenom of the moment, all around the game. Baseball writers are redirecting travel toward Wrigley at their publication's command.
Cubs fans are waking up every day looking forward to games on the big-league level like they haven't in a long time. A lineup with Baez, Starlin Castro, Anthony Rizzo, Arismendy Alcantara and even a rejuvenated Chris Coghlan makes August baseball feel relevant.
Javy is just the latest in what is going to be an onslaught of Cubs prospects to dissect.
Next month, we'll probably meet Jorge Soler. Kris Bryant may come, too, or perhaps not until next June. Albert Almora could find his way to the outfield sometime in 2015.
When do we get Addison Russell at shortstop? Will Kyle Schwarber keep slugging his way through the system quickly? How far away is young center fielder Billy McKinney?
They won't all work out, of course, and they don't have to. There's enough volume that you can afford a miss or two. And if you decide to cut bait before other teams get wise, go get some much needed pitching in trade.
Theo Epstein is banking on right-handed power hitters being the new market inefficiency. Corner that market as best you can and go from there.
For now, Cubs fans have Javy.
We love that young band and ballplayer because the possibility exists that the truly great may have just arrived before our eyes. They have to show up some time.
We didn't know Mike Trout was going to be this good, this consistently. I didn't know that Fleet Foxes' second album would be even better than their first.
So we pay attention. We let our minds wander toward those Sheffield comparisons, like I hear CSNY in Fleet Foxes.
And we hope the music keeps getting better.
• Matt Spiegel co-hosts "The McNeil & Spiegel Show" 9 a.m. to 1 p.m. Monday-Friday on WSCR 670-AM. Follow him on Twitter @mattspiegel670.