Do the D'Addario EJ15 Phosphor Bronze Extra Light strings have an anti-corrosion coating, and how does this affect their longevity compared to the regular D’Addario acoustic string sets?

The D'Addario EJ15 Phosphor Bronze Extra Light strings do not have an anti-corrosion coating; they are uncoated. This means their longevity is similar to other regular, uncoated D’Addario acoustic strings, so they may not last as long as coated strings, but they provide a bright, natural tone preferred by many players.

Are the D'Addario EJ15 Phosphor Bronze Extra Light strings suitable for vintage acoustic guitars with delicate tops, or would you recommend a different gauge to minimize tension?

D’Addario EJ15 strings are Extra Light gauge (10-47) and are designed to be gentle on vintage acoustic guitars with delicate tops, offering lower tension than standard strings. However, silk and steel strings have even lower tension and are softer on older instruments. If your guitar is especially fragile, silk and steel may be the safer choice, but EJ15s are a good option for most vintage guitars needing light tension.