Play alongs are great for a few reasons. First, most play alongs are recorded to a click track, so the drummer is using a musical metronome while exploring a new groove or style.
Second, if you are a band director, and your drummer wants to practice a new groove with music before trying it out with band, this is a great way to do that. When learning a Bossa Nova, for instance, they can take the time to hear and feel the how the bass drum matches the bass guitar without the concern of watching the band director and reading a chart. Those are all very important, but if the drummer is struggling to play the beat they won't be able to hold the band together while focusing on other things. As the band director, you don't want to have to give your drummer the "what is going on back there?" look at a 7am rehearsal. The coffee hasn't even kicked in yet. And as a drummer, who has been the recipient of that look before, I can guarantee you no drummer wants any part of that. This concept holds true for any drummer, in any playing situation. They must feel confident with their groove so they can support the rest of the band.
And last, with situations where a drummer does not have access to a band, as in our current distanced learning times, when bands are not meeting, or, a drummer who is not in any kind of band at all, with play alongs, improvement and forward progress can be achieved.
Oh yeah, one more thing, playing along with music is just plain fun!
The full length play alongs are all available in the members section of Drum Highway.