So, to handle this case with elegance, and also comment the code i will modify it to have: 

```python
try:
    from picard.plugin import PluginPriority

    register_track_metadata_processor(standardise_performers,
                                      priority=PluginPriority.HIGH)
except ImportError:
    log.warning(
        "Running %r plugin on this Picard version may not work as you expect. "
        "Any other plugins that run before it will get the old performers "
        "rather than the standardized performers." % PLUGIN_NAME
    )
    register_track_metadata_processor(standardise_performers)
```

See https://github.com/zas/picard/commit/23ef8465f93e993d794dd8b13e06e581fb8a344d (added to https://github.com/Sophist-UK/picard/pull/4)