Is there a link between violent song lyrics and crime, or is making such an assumption baseless and perhaps just bigotry?
The City of Los Angeles has published crime data dating from 2010 to present (in time of writing this, Oct 2017). The data is available here: https://catalog.data.gov/dataset/crime-data-from-2010-to-present
As their descriptions suggests:
This dataset reflects incidents of crime in the City of Los Angeles dating back to 2010. This data is transcribed from original crime reports that are typed on paper and therefore there may be some inaccuracies within the data. Some location fields with missing data are noted as (0°, 0°). Address fields are only provided to the nearest hundred block in order to maintain privacy. This data is as accurate as the data in the database.
Billboard publishes USA-wide charts for decades. The charts are available here: http://www.billboard.com/charts, and can be accessed through this Python API: https://github.com/guoguo12/billboard-charts. The "Hot-100" (http://www.billboard.com/charts/hot-100) chart combines radio airplay, sales data, and streaming data, or as they put it:
This week's most popular songs across all genres, ranked by radio airplay audience impressions as measured by Nielsen Music, sales data as compiled by Nielsen Music and streaming activity data provided by online music sources.
Azlyrics.com provide lyrics for songs that can be accessed through this Python API: https://github.com/mracos/python-azlyrics.