you should, might have to adjust level in the settings, i would turn up the phone to about 90 (of 100% vol) to get less "background" noise.
depending on what you want to record, might wanna check the legal aspect of it first.
e.g. some states/places require you to inform and get consent from the other party, if recording lets say a phone call.
You might have to use some splitter cable. Plugging a jack into the phone will probably turn its internal speaker off, and will mute the microphone as well. You have to make some tests and see what happens with your phone.