You should be able to designate other services within the GOOGLE HOME APP from your Smart Phone.  If you don't have a Smart Phone and want to use a PC, it can be more difficult.  Currently you would have to download an Android Emulator and information is online for how to do that so you can then get the APP and control your settings.  Default can be set to your choice but make sure you also LINK your accounts with the APP you want to use such as PANDORA or SPOTIFY or SIRIUS...whatever.  My issue is still unresolved as my default is set to PANDORA and you may have the same issue even after setting your default buy my boyfriend in TX has no issues with his devices on PANDORA.  I believe there may be issues with the LOCAL PANDORA network here in Orange/LA County.  Even though I have Pandora as the default, my devices just stop mid song all the time.  See above POST.  I will not buy another single GOOGLE HOME device until they fix the issue.  I do not like their YOU TUBE MUSIC except for videos I may want to watch.  Their algorithms do not work and I hear music from different genres. ... View more