You can also use Smart Tempo with MIDI regions in a project. MIDI regions always follow the project tempo, and so behave similarly to flexed audio files with the Flex & Follow region setting set to On. Because MIDI regions have no source audio file, the Smart Tempo analysis and any edits you make in the Smart Tempo Editor are saved directly to the MIDI regions and stored with the project.
Using Choose the Flex & Follow setting. You can change the default settings for the Flex & Follow region parameter for new recordings and imported audio files in the Tracks area and choose the corresponding command from the shortcut menu). In the dialog, make sure both the “Align downbeat to nearest project downbeat” and “Maintain relative position of all other regions” checkboxes are selected, then click Apply. This writes the analyzed tempo from the selected region to the Tempo track, aligns the selected region to the downbeat, and maintains the relative positions of the other regions (as well as other data such as automation curves) to the analyzed region. Using this workflow, tempo-synced regions (such as Apple Loops or Session Player regions) and effects added to the project also conform to the project tempo.
Download the guides:
Logic Pro User Guide: PDF