Upon further review

...
I think I can forget about the widget and just have the tv defined as text, delimiting the titles with a
comma for example
Then it looks like I need to do something like this in the document template :
[[test_util? &passed_list='name_of_template_variable']]
Where the snippet "test_util" will deal with it like this
$passed_list = array_key_exists($passed_list, $modx->documentObject) ? $modx->documentObject[$passed_list][1] : 'album1';
$titles = explode(',', $passed_list);
[...]
At least I think that’ll work ...
Matt