Must see towns along the Adriatic

Ravenna , beautiful sixth century mosaics , and an absolutely charming city .

Over three trips these are the towns we've visited.

Alberobello, Matera, Polignano a Mare, Bari, Giovinazzo, Trani, Ostuni, Taranto, Gallipoli, Lecce, Brindisi, Vieste, Vasto, Pescara, Ascoli Piceno, Ancona, Senigallia.

We weren't as impress with some of the larger towns, but all of the ones listed definitely did not disappoint.

Your best bet is to see which ones speak to you.
The town your husbands family is from is between Alberobello and Matera.

Are you looking at flying in and out of Bari? (Brindisi works too) Pinpoint the location further, as otherwise you will suggestions the entire length of the Adriatic.
Puglia is full of attractive coastal locations, then then it dims a bit for me until you get into Marche (the coast in between is mostly flat).
Tell us how much time you have as well. Sounds wonderful!

We'll be there about a month. We are flying in and out of Rome. I know multi city tickets are the way to go but we were able to get extremely reasonable tickets in and out of Rome. We are dedicating 2 of the 4 weeks in the southern region and driving up the coast, ending up in Umbria for the jazz festival. Thanks for the great suggestions. Matera is on our list. We do love the ocean so we're open to any coastal towns worth seeing.

Lucky you!
With two weeks, you can see Puglia from end to end. In Basilicata, but Matera is pure magic. I'd base near there, in or near Lecce, and in the Itria Valley. I am a sea/beach lover, but I stayed in those areas and day tripped along the coast. I liked staying in Monopoli as well. You could add Otranto or Gallipoli to get that fix, or stay in one of the smaller spots if that's more your thing (off-season a lot of the coast feels shuttered though).
Deduct the time in Rome (for recovering, night before flight, etc.) and the time for Spinazzola, and then you know what you have to work with for the route to and time in Umbria. I liked Ascoli Piceno very much and would most definitely include it. You will likely have moved inland by the time you get to Umbria, but le Marche has a couple coastal gems (Senigallia, the Monte Conero peninsula). The hard part will be limiting the options in Umbria--I know that part was hard for me in neighboring Marche--too much prettiness, too little time.
enjoy!

Favorites along the coast.

Polignano a Mare, Ostuni, Giovinazzo, Trani, Vasto , Senigallia. Pictures you'll find do not do them justice.

Thanks so much for the great advice and suggestions!

Oh my...Ostuni looks gorgeous!

Down the coast Polignzno a Mare, Monopoli, Lecce. Ostuni is a bit overtouristed.
North of Bari, Trani.
And Old Town Bari is very interesting. The Basillica of St. Nicholas is avpilmgrimage site as St. Nicholas’ relics( bones) are there. Yes, it is THE St. Nicholas, i.e. Santa Claus.
The Adriatic is beautiful, blue green water.

I loved Matera - but there are so many places to see. A great book about this area and the history and poverty...

"Christ Stopped at Eboli" is a memoir by Carlo Levi

Toured the Sassi and the caves etc. Interesting area.
My RS tour stayed at the Hotel Sassi - parts of the hotel are carved out
of the Sassi stone area.

Although very pretty, I was disappointed with Ostuni. Similarly, I expected to love Lecce, and didn't - it's not that I hated it, but it failed to strike a chord.
I really enjoyed the Otranto, Gallipoli (technically on the Ionian coast?), the old quarter of Bari, the medieval parts of Monopoli and the cathedral and restaurants of Trani.

With a month you could consider taking the ferry from Bari across to Dubrovnik.