Music on iPhone does not show up in iTunes

Hi!

Apologies if this is old hat - my searches in this forum (or anywhere else) did not turn up an answer.

For a couple of weeks now, most of the music on my iPhone 5s (iOS 8.3), some 26 GB, does not show up in iTunes (12.1.2.27).

The vast majority of the music is stuff I ripped from CD's or from other sources than iTunes Store. Coincidentally, the only music which iTunes shows to be on the phone is the 195 MB's worth I actually bought on iTunes Store, plus one album I put on the phone after this problem began.

iTunes on the Mac has about 78 GB of music.

My settings include administering music and videos manually and iTunes Match is switched off.

When the phone is connected, the contents bar in iTunes will initially show the correct amount of space taken up by music, then at some arbitrary time and for no apparent reason it switches to show a space consumption equivalent to the above 195 MB. The music, however, is still on the phone.

I used to be able to connect the phone, choose it on the icon in iTunes and then see the music content in the column browser.

Any hints or ideas towards a solution greatly appreciated.

Best regards, Ole