Strummed all at once, the open strings are a big, bold Dsus4 chord. It’s a de facto standard alternative to traditional E standard (EADGBE) tuning amongst fingerpickers and percussive players alike.

Once you've whetted your appetite for open tuning experimentation, your acoustic guitar having long forgotten the vanilla pleasures of EADGBE ... t disrupt your neck/string tension much, either ...