it's not disappeared, you must just be listening to music without it.
btw, radio often get a number of promo only mixes with "w/o guitar" or "w/o rap" edits removing the solos and raps to shorten a track for a more concise short version to fit 3 minute spots to avoid the dj cutting the track short or talking over the solo. so if most of your music listening is via standard commercial radio stations or mtv etc you aren't going to hear a lot of solos
btw, radio often get a number of promo only mixes with "w/o guitar" or "w/o rap" edits removing the solos and raps to shorten a track for a more concise short version to fit 3 minute spots to avoid the dj cutting the track short or talking over the solo. so if most of your music listening is via standard commercial radio stations or mtv etc you aren't going to hear a lot of solos



