Here are some birds I photographed in Arizona but couldn't confidently identify by species. After considering comments I received after posting, I've made tentative identifications.

The Solitary-type flycatcher was photographed at Agua Caliente Park in Tucson; it appears to have a very slight yellow wash on the flanks, which led one birder who saw my photos on the spot to lean toward calling it a Cassin's, while allowing that it was in the difficult intermediate area. Two California birders with lots of experience of Cassin's leaned strongly toward calling it Plumbeous, thinking the gray was too uniform for Cassin's, and noting that faint yellow wash was consistent with Plumbeous.

The empids were all photoed along Madera Creek. Bird A was photoed on April 17 below Santa Rita Lodge, birds B, C, and D at Madera Picnic Area on April 20, and Bird E on April 19 along Madera Creek at Procter Road. I didn't hear any vocalizations, or observe anything beyond what is shown in these photos that might help with the identification. I'm not experienced at all with empids in migration, but I've now made tentative identifications where possible after considering the comments of experienced birders.