Vocal Synthesis, a groundbreaking new technology that puts sung vocal lines within easy reach of instrumentalists, was developed by Casio in conjunction with researchers at the Nagoya Institute of Technology. Articulation models based on earlier machine learning research are used to modulate vocal tones from a range of virtual vocal patches known as Vocalists, combined with built-in preset lyrics and user-programmed lyrics entered into the Lyric Creator app to produce fluently sung lines via the keyboard. The vocals, which are created by combining vocal tones produced by a PCM sound source designed to mimic human vocal cords, together with filters that generate phrasing in accordance with the lyrics input, can also be tweaked in real time via physical knobs to further adjust characteristics such as age and gender.

This technology is a radical departure from prior approaches that triggered pre-recorded vocal sounds via a keyboard, or vocoders, which combine sung vocals in real time with synthesizer tones. And as well as eliminating the need for special techniques, Vocal Synthesis allows you to pair your pre-programmed lyrics with any melody or harmonies you wish, opening up new possibilities at the nexus of instrumental and lyrical expression.

How the lyrics advance is determined by one of two modes: Note Mode, in which the notes you play form the melody and the lyrics advance with each note played ; and Phrase Mode, which steps through the lyrics automatically at a fixed meter as you play.

Note Mode produces fluent, natural-sounding vocal lines by triggering each syllable of your lyrics according to the notes you play and applying the terminal consonants as you release the keys. There are also several features to guard against the risk of losing your place having played a wrong note. Casio’s SP-3 and SP-20 pedals (sold separately) or other commercially available footswitch can be used to step forward and backward through the lyrics , or reset the lyric position. You can also select which syllable to pronounce next using the bass register keys, and control how syllables should advance when chords are played.

While Note Mode—and existing vocal synthesis software—largely demand that the vocal melody is fixed in advance, in Phrase Mode, however, the CT-S1000V gives you options for improvisation by moving the lyrics forward automatically as you play. Simply set up the lyrics and their rhythmic subdivisions and BPM in advance, and then play freely and hear the lyrics being sung along in time.

This mode allows you to move beyond simple conceptions of melody, and create complex vocal lines based on advanced keyboard techniques. At the same time, if your keyboard skills are more basic, you can still be confident that the phrasing will not ‘break’ if you accidently hit some wrong keys. Another benefit of Phrase Mode is natural phonetic junctures that create flowing vocal passages. This also provides a great compositional platform, allowing you to work out new vocal lines and develop arrangements via the intuitive interface of the keyboard.

Indeed, it is Phrase Mode that takes the CT-S1000V beyond simply a new keyboard with new sound generators and tones, transforming it into an instrument that opens up new possibilities for musical expression.

Favorite song lyrics and original creations alike can be entered in English and Japanese using your iOS or Android device via Casio’s own Lyric Creator app. This text is automatically divided into syllable units (though you can also assign divisions manually and group multiple syllables together), and after exporting the resulting data to your CT-S1000V, you’re ready to play.

In Phrase Mode, the playback meter of the lyrics is determined by assigning note values (8th notes, quarter notes, etc.) to the individual syllable units and inserting rests. Individual lyric tones include tempo data that can be adjusted via the CT-S1000V itself. Tempo can also be synced to the MIDI clock from your DAW or other external MIDI device to ensure that your vocal phrasing always remains in time regardless of how adventurous you get.

While Lyric Creator places a limit on the length of lyric that can be entered (up to 100 eighth-note syllables), once uploaded to your CT-S1000V, individual lyrics can be chained together into much longer sequences. This function allows you to fine tune individual sections at the input stage before combining them within your CT-S1000V to create a complete song.

The Lyric Creator app can also be used to transform a WAV audio sample (16bit/44.1kHz, mono/stereo, max. 10 seconds in length) stored within your smart device into an original Vocalist patch that can then be loaded into the CT-S1000V. The editing interface allows you to set characteristics such as age, gender, vocal range, and vibrato.

The CT-S1000V’s 22 Vocalist presets have each been designed for maximum clarity of enunciation by blending different waveforms with elements such as white noise, and as such User Vocalist waveforms may not achieve the same level of articulation. But with some experimentation you can create new sounds, including abstract ones akin to the CT-SV1000V’s Animal preset.

Start experimenting by downloading a free User Vocalist-compatible waveform sample (SawC4+WhiteNoise.wav) from the link below:
https://support.casio.com/en/support/download.php?cid=008&pid=20

Once the Lyric Creator app is installed on your smart device, you can start transferring lyrics, sequences, vocal samples, etc., by connecting your device to your CT-S1000V via a USB cable. While connected, you can also use the app to view how much space is available on the CT-S1000V’s internal drive, delete files, and edit file names. Program files are exported using a proprietary format that enables sharing between CT-S1000V users. You can also import Music XML lyric data and note values from your DAW.