Probably record a wav and use a wav to midi converter.

According to the Handset Compatibilty Guide on the Yamaha SMAF Global
Website, the Motorola T720 (CMDA) supports the Yamaha mobile audio
synthesizer LSI "MA-3". The T730 (CDMA), while not listed, appears to also
support this.

For MIDI files as ring tones, Per the SMAF docs, "Please use Standard MIDI
File Format 0" and "Midi channels from 1 to 16 can be used."

For "voice" style ring tones from WAV or MP3 files... Wav/MP3s to be
converted into Ring Tones must be MONO, 16bit Audio Sample Size, and 4 or
8kHz Sample Rate or else the conversion will not work. You will also need
the WSC-MA2-SMF tool to convert from WAV/MP3 to an MMF file suitable for
loading on the phone. The tool is available from the Tools link from the
Yamaha Global site.

Once you've downloaded and installed it, you basically launch the
WSC-MA2-SMF.EXE, drag/drop a WAV file onto it, and it outputs a .MMF file
that you can load onto the phone.

(If you are using PST to load your ringers on the phone, .MMF files must be
renamed to .MID if you are going to use them with EMS manager to edit the
M-Services Backup file)

To play back the .MMF file on the PC, use the DirectPlay option in the
ATS-MA3-SMAF tool (separate dowload from the Tools link). Or you can search
the web for PSMPlay 3.80e or MMFPlayer

I have used this to convert several WAVs to ringers for use on my Moto T730
CDMA (Verizon). Any MP3s that I started with I saved as WAV when I converted
them to MONO, 16bit/8kHZ, so I have not tired dropping an MP3 onto the
WSC-MA2-SMAF program.