Nahawand 4 and Ajam 6 are the closest ajnas to Bayati, so close that actual "modulation" among them is often quite ambiguous. Sometimes the Nahawand is so strong (see "Ba3eed 3annak" #29 below), or the Ajam is so strong (See "Samai Bayati" #29-#32 below), that we can clearly identify them as distinct tonicizations. But more often, as you will see below, melodies flow continuously through these ajnas without a clear break, or a definitive tonicization. I find that I can hear alternate options for how to parse many of these melodies. One of the most emblematic Bayati melody patterns is a descent from the 6th scale degree (6-5-4-3--5-4-3-2--4-3-2-1 and variants on that; the Taslim of "Samai Bayati" is basically this melody elongated), and to determine whether it begins on Ajam 6, or the third degree of Nahawand 4, or the 6th degree of Bayati 1, is not always easy or definitive. All three of these ajnas overlap each other. A Western-trained musician will note that the relationship between Nahawand 4 and Ajam 6 is the same as the "Relative Minor to Relative Major" relationship--a relationship that rarely occurs elsewhere within the maqam system, but one which is prominent and ambiguous within Bayati (see especially the opening of the famous song "Ah Ya Hilu"). Therefore, all I can say about the analyses below is that they are my best attempts, and those of which I am least confident among all those presented on this site.
From "Nura Nura"
From "Samai Bayati il-3ariyan"
From "Taheya"
From "Ah Ya Hilu"
From "Ba3eed 3annak"